O’Reilly Verlag

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    Inhaltsverzeichnis | Index | Probekapitel | Kolophon | Rezensionen |
    

Tony Bautts, Terry Dawson & Gregor N. Purdy

Seiten 362

EUR34.00, SFR57.90

[ Numbers ], [ A ], [ B ], [ C ], [ D ], [ E ], [ F ], [ G ], [ H ], [ I ], [ J ], [ K ], [ L ], [ M ], [ N ], [ O ], [ P ], [ Q ], [ R ], [ S ], [ T ], [ U ], [ V ], [ W ], [ X ], [ Y ], [ Z ],
Symbols
* (asterisk), 61, 110
@ (at sign) (see at sign)
{} (braces), 79
[] (brackets), 68, 167
: (colon), 67, 184, 242
, (comma), 182
$ command (sendmail), 223
$= command (sendmail), 223
. (dot) (see dot)
:: (double-colon), 235, 242
= (equal sign), 94
! (exclamation point), 184, 256
! flag (netstat), 61
> (greater than) sign, 181, 202
- (hyphen), 102, 110
< (input redirection), 37
< (less than) sign (sendmail), 202
$# metasymbol, 201, 203
$* metasymbol, 200, 202
$+ metasymbol, 200
$- metasymbol, 200
$: metasymbol, 201, 203
$= metasymbol, 200
$@ metasymbol, 200, 201, 203
$~ metasymbol, 200
- (minus sign), 37, 58
+ (plus sign), 94, 256
# (pound sign) (see pound sign)
" (quotation marks) (ssh), 177
; (semicolon), 79
' (single quotation mark), 194
/ (forward slash), 78, 164

Numbers[ Top ]
16450 UART chip, 34
16550 UART chip, 34
-6 option (OpenSSH), 242
802.11 standard, 295
802.11a standard, 4, 295
802.11b standard
      client configuration, 297-300
      hardware and, 296, 297
      LANs and, 4
      laptops and, 294
      Linux access point configuration, 300-305
      overview, 295
      troubleshooting, 305-306
802.11g standard
      802.11b versus, 297
      LANs and, 4
      laptops and, 294
      overview, 295
802.11i standard, 295
802.11n standard, 296
802.15 working group, 295
802.16 working group, 295
8250 UART chip, 34

A[ Top ]
A record
      address resolution, 82
      FQDNs and, 75
      as glue record, 77
      hostcvt tool and, 91
      hostnames and, 81
A record (continued)
      nslookup and, 89
      purpose, 79
      type option and, 80
-A subcommand option (iptables), 136
AAAA record, 81
ABORT keyword (chat), 102
absolute names, 79, 80
Absolute Value Systems, 300
ACCEPT target (iptables), 126, 131, 132
access control, 163, 164, 270-272
access control lists (ACLs), 286
access database, 208, 211, 217-219
access points (wireless networks), 298, 299, 300-305
access_db feature, 211, 217
ACLs (access control lists), 286
action items, 68
Active Directory, 266
active hubs, 4
active-filter option (pppd), 114
add argument (route), 50
add-alias command (djbdns), 94
add-host command (djbdns), 94
addif option (brctl), 307
add-ns command (djbdns), 94
address resolution
      A records and, 82
      BIND and, 66
      defined, 8
      of external machines, 94
      overview, 19, 20
Address Resolution Protocol (see ARP)
addresses (see IP addresses; MAC addresses)
adduser utility, 112n
ad-hoc mode, 297
adsl-setup script, 116
adsl-start script, 117
advanced policy routing, 11
AF_ ROSE socket, 11
AF_ X25 socket, 11
AF_ATMPVC socket, 11
AF_ATMSVC socket, 11
AF_AX25 socket, 11
AF_INET socket, 11
AF_INET6 socket, 11
AF_IPX socket, 11
AF_NETROM socket, 11
AF_UNIX socket, 11
AirSnort tool, 296
Albitz, Paul, 66
alert messages, 261
aliases
      canonical hostnames and, 82
      CNAME records and, 79
      configuring for interfaces, 57
      email addresses and, 183
      genericstable database and, 216, 217
      hostcvt tool and, 91
      hostnames and, 75
aliases database
      genericstable database and, 216
      overview, 211
      sendmail and, 206, 212
aliases field (services), 168
ALL EXCEPT keyword, 164
ALL keyword, 164
Allman, Eric, 179, 186
ALLMULTI flag (ifconfig), 60
allmulti option (ifconfig), 60
allow-recursion option (named.conf), 78
allow-transfer option (named.conf), 78
AlohNet project, 294, 295
amateur radio, 6, 11, 19
anonymous users, 261, 286
anonymous.newsgroups directory, 261
Apache Software Foundation, 249
Apache web servers
      background, 244
      configuration file options, 247-250, 255
      configuring and building, 244-247
      IPv6 and, 240, 241
      OpenSSL and, 252-256
      overview, 244
      security considerations, 15
      troubleshooting, 256-257
      VirtualHost functionality, 250-252
apache.conf file, 241
apachectl tool, 250, 256
Apache-SSL, 252
--append subcommand option (iptables), 136
APPENDDEF macro (Build), 190
Appletalk, 11, 96
apt-get utility, 306
apt-get utility (Debian), 120, 306
Argonne National Laboratory, 291
ARP (Address Resolution Protocol)
      ifconfig options and, 59
      overview, 19, 20
      proxy, 56, 64, 104
arp option (ifconfig), 59
ARP tables, 63, 65
arp tool, 20, 63, 64
ARPANET, 2, 180
ASCII characters, 105, 106, 304
asterisk (*), 61, 110
asynch map, 105, 106
asynchronous communications, 5, 6, 105
Asynchronous Control Character Map, 105
Asynchronous Transfer Mode (ATM), 6, 11
asyncmap option (pppd), 106
AT command set, 39
at sign (@)
      dot and, 80
      group names and, 272
      Internet email address and, 202
      origin and, 79
      SOA record, 76
ATM (Asynchronous Transfer Mode), 6, 11
attacks
      ifconfig option and, 60
      inetd.conf file and, 162
      man-in-the-middle, 172
      methods of, 120-122
      named.conf and, 78
      system security and, 13
      on WEP, 296
      xinetd and, 164, 165
ATTEMPT suboption (xinetd), 166
ATZ command, 101
auth facility (syslog), 163
authentication
      access points and, 301
      chap-secrets file, 109
      Cyrus IMAP and, 264
      IMAP and, 261
      LDAP and, 289
      OpenLDAP and, 280, 285, 286
      PAP and, 111
      PPP and, 108-111, 113
      pppd and, 99, 109
      Samba and, 269
      security considerations, 15, 60, 107
      servers and, 96
      ssh daemon and, 172
      wireless networks and, 295, 299
authoritative nameservers, 75
authorization, 96, 269
authorized_keys file, 174, 178
autoconfig parameter (setserial), 35
auto_irq parameter (setserial), 35
automake configuration script, 46, 259
automatic dialing, 100-102
autonomous systems, 21
AX.25 protocol, 6, 11, 19
Aznar, Guylhem, 180

B[ Top ]
backend database (BDB), 280
bang path notation, 184
baseband modulation (base), 4
Bastille Linux, 14
Bcc: field (mail header), 182
-bd argument (sendmail), 228
BDB (backend database), 280
beacons, 299
Beale, Jay, 14
Berkeley Internet Name Domain service (see BIND service)
Berkeley Socket Library, 10
BerkeleyDB, 265, 280
Bernstein, D.J., 66, 92
bestmx_is_local feature, 213
BGP (Border Gateway Protocol), 25
binary data, XON/XOFF handshake and, 33
BIND (Berkeley Internet Name Domain) service
      address resolution and, 66
      alternatives to, 92-95
      dig tool, 84, 87, 88
      hostcvt tool, 91
      named.conf file, 77-79
bind interface, 270
BindAddress option (Apache), 247
binding
      addresses and ports, 247
      Samba and, 270
Biro, Ross, 11
bitdomain database, 220
bitdomain feature, 220
BITNET networks, 220
biz top-level domain, 72
blacklist_recipient feature, 218
Bluetooth, 295
BNC connector, 3
BOOTP protocol, 20
Border Gateway Protocol (BGP), 25
bounced mail, 183
braces {}, 79
brackets [], 68, 167
brctl program, 306, 307
BREAK (carriage return), 102
Brewery, Virtual, 309
bridges/bridging
      DSL modems and, 116
      wireless networks, 306-307
broadband wireless systems, 295
broadcast address, 18
BROADCAST flag (ifconfig), 59
broadcast option (ifconfig), 59
broadcasting
      defined, 19
      eavesdropping and, 122
      Ethernet and, 56, 60
browsable command (Samba), 271
-bs argument (sendmail), 228
BSD print system, 273
BSD remote services, 120, 121
BSD routed daemon, 25
buffers, UART chips and, 34
bug databases, 120
Bugtraq database, 120
Build utility, 190-191, 209
Burgiss, Hal, 116
BUSY message, 102
bytes_from field (mailstats), 230
bytes_to field (mailstats), 230

C[ Top ]
-c argument (Build), 191
.C command (sendmail), 223
C command (sendmail), 198, 199
-c option (iptables), 135
cable modems, 30
cacert.org organization, 252
cache option (named.conf), 79
caching-only servers, 75, 78, 83, 98
Callahan, Michael, 97
callout (cua) devices, 31
/canon command (sendmail), 223
canonical hostname
      A record and, 81
      aliases and, 82
      defined, 75
      SOA record and, 80
card identification, 305
cardctl command, 305
carriage return, 102
case sensitivity, 113, 193
Cc: field (mail header), 181
CCITT, 179
cellular phones, 233
certificates
      OpenLDAP and, 290
      OpenSSL and, 262
      SSL and, 252, 253
      troubleshooting, 293
chains
      iptables and, 126, 130, 134
      packets and, 131
      policies for, 131
      rules and, 149
Challenge Handshake Authentication Protocol (see CHAP)
channels
      defined, 298
      HostAP and, 303
      iwconfig tool and, 300
      troubleshooting and, 305
CHAP (Challenge Handshake Authentication Protocol)
      authorization and, 96
      chap-secrets file, 109, 111
      mgetty program and, 113
      PAP and, 108, 109
      PPP and, 108, 113
      pppd and, 97, 99
chap-secrets file, 109, 111
chargen internal service, 161
chat program, 97, 100-102
checksums, 15, 96, 129
chipsets, 296, 297
choke points, 122
CIDR (Classless Inter-Domain Routing)
      address scarcity and, 233
      block notation, 19
      IP addresses and, 18
      notation used, 138
      overview, 234
CIFS (Common Internet File System), 266, 267
cipher, SSL, 290
Class A networks
      address ranges, 18
      IANA and, 45, 233, 234
      nslookup and, 89
      overview, 17
Class B networks
      address ranges, 18
      IANA and, 45, 234
      overview, 17
      subnetting and, 48
Class C networks
      address ranges, 18
      CIDR and, 234
      IANA and, 45
      overview, 17
      subnetting and, 48
Class D networks, 17
Class E networks, 17
Class F networks, 17
class field (resource record) (DNS master file), 79
Classless Inter-Domain Routing (see CIDR)
Clear to Send (CTS), 33
clients
      802.11b standard and, 297-300
      certificates and, 252
      Ethernet addresses and, 20
      listening for, 10
      ports and, 10
      PPPoE, 116-118
      RPC and, 169
      testing IMAP, 263
      ucspi-tcp program, 92
clocal flag (stty), 38
cmdline field (inetd), 162
CNAME record
      canonical hostname and, 75, 81
      purpose, 79, 82
coaxial cable and, 3
Collier-Brown, David, 266
collisions, 4
colon (:), 67, 184, 242
com top-level domain, 72
Comer, Douglas R., 16
com_err.h file, 265
comma (,), 182
comments
      DNS, 78
      nsswitch.conf, 67
      pppd, 99
      r command, 171
      sendmail.mc file, 192
Common Internet File System (CIFS), 266, 267
Common Unix Printing System (CUPS), 274, 275
Common Vulnerabilities and Exposures (CVE) database, 120
communications software, 29, 30
Compressed SLIP (CSLIP), 8
confDONT_PROBE_INTERFACES variable (m4), 213
confEBINDIR variable (m4), 205
confHOST_STATUS_DIRECTORY variable (m4), 230
configtest option (apachectl), 250, 256
configuration files
      Apache web servers, 247-250, 255
      COPS program, 14
      dhcpd.conf file, 47
      djbdns resolver and, 93
      mgetty program, 39, 40
      named.conf, 77
      OpenLDAP and, 281, 282, 288, 290
      PPPoE clients, 117
      printcap file, 274, 275
      remote login and execution, 170-178
      resolver functions and, 67
      RPC and, 170
      Samba and, 269, 277
      sendmail, 179, 190, 191, 192-198
      testing with apachectl, 256
      troubleshooting, 257
      xinetd and, 166, 167
configuration utilities, serial ports and, 34-38
configure program (OpenLDAP), 281
confTRUSTED_USERS option (FEATURE), 219
confUSERDB_SPEC option (define), 219
connect command, 114
CONNECT message (chat), 101
connect option (pppd), 100, 107
Connect: tag field (sendmail), 218
connection tracking, 150, 157
contact field (SOA RR) (DNS master file), 80
continue option (nsswitch.conf), 68
control characters, 106
converting binary to hexadecimal, 106
COPS program, 14
Costales, Bryan, 186
country codes, 73
Cox, Alan, 11
cp command, 177, 210
cps option (xinetd), 166
cron jobs, 13, 228
crontab file, 231
crtscts flag (stty), 36, 37
crtscts option (pppd), 98, 113
crtsdts flag (stty), 38
cs5 flag (stty), 38
cs6 flag (stty), 38
cs7 flag (stty), 38
cs8 flag (stty), 38
CSLIP (Compressed SLIP), 8
cstopb flag (stty), 38
CTS (Clear to Send), 33
cua (callout) devices, 31
CUPS (Common Unix Printing System), 274, 275
CustomLog option (Apache), 248
CVE (Common Vulnerabilities and Exposures) database, 120
cyrus argument (MAILER macro), 196
Cyrus IMAP, 259, 263-265

D[ Top ]
-d built-in match (iptables), 137
.D command (sendmail), 223
D command (sendmail), 198, 199
-d command (sendmail), 223
-d option (arp), 64
-D subcommand option (iptables), 136
daemon facility (syslog), 101, 112
daemon wrapper, 163
daemons, 160, 162, 171
daemontools program, 92, 93
DARPA (Defense Advanced Research Projects Agency), 2
Data Carrier Detect (DCD), 38, 101
data communications equipment, 5
data terminal equipment, 5
Data Terminal Ready (DTR), 40
databases
      LDAP and, 278
      sendmail, 210-222
datagrams
      broadcasting, 19
      congested networks and, 55
      firewall packet logging and, 133n
      hops for, 26
      hosts and, 20, 21
      netstat command and, 61
      packets as, 2, 7
      routing, 24-26
      subnets and, 21
      traceroute and, 63
      UDP and, 9
      Van Jacobson header compression, 97
data-only keyword (mgetty), 40
Date: field (mail header), 182
daytime internal service, 161
DCC (Direct Communications Channels), 157
DCD (Data Carrier Detect), 38, 101
DDI (Device Driver Interface), 12
Debian, 120, 288, 306
debug keyword (mgetty), 40
debugging, PPP and, 112
DECnet, 196
default route, 18, 24, 25
default-lease-time option (DHCP), 47
defaultroute option (pppd), 99, 104
Defense Advanced Research Projects Agency (DARPA), 2
define command (sendmail)
      databases and, 219
      lowercase and, 193
      overview, 190, 195
      sendmail.cf and, 198
      sendmail.mc and, 192
      setting maximum headers, 206
del argument (route), 50
--delete subcommand option (iptables), 136
--delete-chain subcommand option (iptables), 136
delimiters, 200
demand dialing, 114, 115
demand option (pppd), 114
denial of service attacks, 121, 150
dependencies, OpenLDAP and, 280
--destination built-in match (iptables), 137
Destination NAT (DNAT), 121, 156, 159
--destination-port match option (iptables), 140
-detach option (pppd), 101, 113
/dev directory, 30
device argument (ip-up), 105
Device Driver Interface (DDI), 12
device drivers, Net-4 and, 11
dgram sockets, 161
DHCP (Dynamic Host Configuration Protocol), 44-48
dhcpcd program, 46
dhcpd.conf file, 47
diald command, 114
dial-up configuration
      authorization and, 96
      dumb terminals and, 38
      IP addresses and, 103
      nameservers and, 69
      persistent dialing and, 115
      proxy ARP and, 64
dig tool (BIND), 84, 87, 88
Direct Communications Channels (DCC), 157
direct keyword (mgetty), 40
directory services, 278
disable configuration option (xinetd), 167
-disable-v4-mapped tag (IPv6), 241
DISCARD action (access rule), 218
discussion lists, 261
Distinguished Names (DN), 279
divert command (m4), 192, 193
djbdns resolver, 66, 92-93
DMZ (demilitarized zone) networks, 122
DN (Distinguished Names), 279
DNAT (Destination NAT), 121, 156, 159
DNAT target (iptables), 127, 159
dnl command (m4), 193
DNS database
      master files and, 79-83
      overview, 75-77
      time to live, 75
      tools used with, 91
DNS (Domain Name System)
      BIND alternatives, 92-95
      IP masquerade and, 158, 159
      name lookups, 74-75
      name resolution and, 28
      named.conf file, 77-79, 83
      nameservers, 75, 87, 88
      newsgroups, 67
      nslookup and, 88-91
      overview, 71-73
      spoofing, 176
      useful tools, 91
      writing master files, 84-87
dns option (nsswitch.conf), 67
dnsip tool, 95
dnswalk tool, 91
DocumentRoot option (Apache), 248
domain field (resource record), 79, 82
DOMAIN file, 194, 205-209
DOMAIN macro (sendmail), 194, 204
Domain Name System (see DNS)
domain names, 47, 202
domain option
      pppd, 110
      resolv.conf, 70
domainname command, 44
domain-name-servers command, 47
domains
      access database and, 218
      authoritative servers and, 75
      country codes, 73
      default, 70
      defined, 71
      hosting on single IP addresses, 251
      hostnames in, 73
      in-addr.arpa, 82
      mail, 82, 183, 184
      master files and, 79
      relay-domains file and, 214
domaintable feature, 220
dot (.)
      absolute names and, 79
      at sign and, 80
      domain names and, 202
      local hostnames and, 164n
      namespace and, 71
dotted decimal notation, 8
dotted quad notation
      ARP tables and, 63
      ifconfig command and, 58
      IP addresses and, 8, 17, 110
      iptables built-in matches and, 138
      netstat command and, 61
      pppd and, 103
      route command and, 54
double-colon (::), 235, 242
down option (ifconfig), 58
--dport match option (iptables), 140
DROP target (iptables), 126, 131, 132
DSA keys, 172
DSL modems, 30, 116
dsmtp mailer (MAILER macro), 196, 197, 204, 220
--dst built-in match (iptables), 137
DTR (Data Terminal Ready), 40
DURATION suboption (xinetd), 166
Dynamic Host Configuration Protocol (DHCP), 44-48

E[ Top ]
-E subcommand option (iptables), 136
eavesdropping, 122
ebtables (Ethernet Bridge Tables), 126
echo flag (stty), 38
Echo Reply message (ICMP), 150
Echo Request message (ICMP), 124, 150
Echo Request message (PPP), 107
Echo Response message (PPP), 107
Eckstein, Robert, 266
edu top-level domain, 72
EGP (External Gateway Protocol), 25
electronic mail
      administration issues with, 179-185
      IMAP and, 258
      serial communications and, 29
      testing, 222
elm mail reader, 181
email addresses
      $: metasymbol and, 203
      access database and, 218
      genericstable database and, 216
      genericstable feature and, 211
      parts of, 183
      relay_from_local feature and, 215
email (see electronic mail)
-enable-v4-mapped tag (IPv6), 241
encryption
      802.11b standard and, 296
      802.11i standard and, 295
      eavesdropping and, 122
      LDAP and, 289
      remote login and, 171
      Samba and, 269
      ssh daemon and, 172
      SWAT and, 276
      troubleshooting, 257
      wireless Ethernet and, 4
end points, TCP and, 9
envelope, 180, 218
equal sign (=), 94
ERROR action (access rule), 219
error messages
      access rules and, 219
      Apache web servers and, 256
      bounced mail and, 183
      certificates and, 252
      ICMP and, 26
      IPv6 notation and, 242
      OpenSSL and, 262
error_log file, 257
ErrorLog option (Apache), 248
ertrn script, 229
escape characters, 105, 106
ESMTP (Extended SMTP), 197
esmtp mailer (MAILER macro), 196, 197, 203, 204, 220
ESSID, 299, 300, 303
Ethernet
      ARP and, 20
      broadcasting and, 19, 56, 60
      IP addresses and, 44
      IP masquerading and, 155
      MAC addresses and, 132, 138
      overview, 3-5
      passive collection of accounting data, 152
      PPP and, 98
      prevalence of, 154
      (see also PPPoE)
Ethernet interfaces, 16, 52-54
Ethernet snooping, 59
ETRN command (ESMTP), 197
Evolution mail reader, 181
--exact option (iptables), 135
exclamation point (!), 184, 256
expect strings, 100, 102
expire field (SOA RR), 81
EXPOSED_USER macro (generic.m4), 207
External Data Representation (XDR) format, 169
External Gateway Protocol (EGP), 25
external routing protocols, 25

F[ Top ]
-f argument (Build), 190
-f built-in match (iptables), 137
F command (sendmail), 198, 199
-f option (chat), 101
-F subcommand option (iptables), 136, 152
Fannin, David, 116
fax argument (MAILER macro), 196
FDDI, 11, 16
FE8x addresses, 236, 238
FE9x addresses, 236
FEATURE macro (sendmail)
      databases and, 219, 220
      generic.m4 file and, 208
      hostnames and, 207
      mailers and, 205
      overview, 195
      pseudo-domains and, 206
      usernames and, 199
FEAx addresses, 236
FEBx addresses, 236
Feigenbaum, Barry, 266
FHS (File Hierarchy Standard), xv
FidoNet, 184
FIFO buffer, 34
File Hierarchy Standard (FHS), xv
files option (nsswitch.conf), 67
files service (nsswitch.conf), 69
filter table (iptables)
      chains for, 134
      as default, 131
      description, 131
      null rule, 132
filtering
      defined, 123
      hosts and, 122
      MAC addresses, 303, 304
      spoofing and, 121
      (see also IP filtering)
finger daemon, 163
finger service, 162, 164
fingerprints, 176, 188
firewall packet logging, 133n
firewalls
      denial of service attacks and, 150
      IP accounting and, 147
      IP masquerade and, 156
      kernel and, 123, 133, 134
      Linux and, x
      methods of attacks and, 120-122
      NAT and, 125
      Net-4 and, 11
      overview, 122, 123
      PPPoE and, 116
      purpose of, 119
      references, 144
      Samba and, 268
      sample configuration, 141-144
      troubleshooting, 243, 293
fixed IP addresses, 47
fixed-address option (DHCP), 47
Fluhrer, Scott, 296
--flush subcommand option (iptables), 136
focus characters, 202
FORWARD hook point (iptables)
      chains and, 127
      DROP target and, 126
      filter table and, 131, 134
      functionality, 129
      MAC match option, 139
      mangle table and, 131
      null rule, 132
forward slash (/), 78, 164
ForwardPath option (sendmail.cf), 206
fourport parameter (setserial), 35
Fox, Karl, 97
--fqdn argument (hostname), 44
FQDNs (fully qualified domain names)
      adding hosts and, 94
      DHCP servers and, 47
      email addresses and, 183
      hostnames and, 44, 203
      NS record and, 77
FRAD (Frame Relay Access Device), 5
--fragments built-in match (iptables), 137
fragmentation, 149, 150
Frame Relay Access Device (FRAD), 5
Frame Relay protocol, 5, 11
frames (see packets)
Free Software Foundation, x
FreeBSD, 12
From: field (mail header), 181
From: tag field, 218
fs file, 67
FSSTND (Linux File System Standard Group), xv
FTP, 148, 156
fullstatus option (apachectl), 250
fully qualified domain names (see FQDNs)

G[ Top ]
G flag (netstat), 61
gated
      defined, 56
      metric value and, 26
      netstat options and, 61
      RIP and, 26
gateways
      configuring, 55
      hops and, 26
      hosts as, 7
      IP and, 24-26
      mail routing and, 184
      netstat command and, 61
      networks and, 22-24
      proxy ARP and, 64
      routing through, 54
generic-linux.mc file
      generic.m4 file and, 205
      modifying, 207
      naming of, 204
      purpose, 203
generic.m4 file, 205-209
GENERICS_DOMAIN macro, 215
generics_entire_domain feature, 215
genericstable database, 208, 211, 215-217
genericstable feature, 211, 215
Gentoo Linux, 260, 267
getdomainname( ) system call, 70
gethostbyaddr( ) function, 27, 67
gethostbyname( ) function, 27, 67
gethostname( ) function, 110
getty program, 38, 39
Gibson, David, 299
glibc library, 67
global Top-Level Domains (gTLD), 72
global unicast address, 236
glue records, 77, 82
GNU General Public License, x
Gnu Privacy Guard (gpg), 187, 188
GNU standard library, 67
gov top-level domain, 72
gpg (Gnu Privacy Guard), 187, 188
GQ, 291
graceful option (apachectl), 250
greater than (>) sign, 181, 202
group ID, sendmail and, 191
GTK+-style interface, 291
gTLD (global Top-Level Domains), 72
guest directive (Samba), 271
GUI, 275, 291

H[ Top ]
H command (sendmail), 198, 199
H flag (netstat), 61
-h option (iptables), 135
handshakes, 33, 36, 105
hardware, 802.11b standard and, 296
hardware Ethernet option (DHCP), 47
hardware field (HINFO RR), 83
hardware handshaking (see handshakes)
hash sign (see pound sign)
HDLC (High-Level Data Link Control), 96, 97, 112
help command (nslookup), 91
--help option (iptables), 135
Hermes chipsets, 296, 297, 299
Hesiod addresses, 75, 79
hexadecimal characters, 106, 304
High-Level Data Link Control (HDLC), 96, 97, 112
HINFO record, 83
holdoff option (pppd), 114, 115
hook points, 127, 129, 131
hops, 26, 26n
host field (MX RR), 82
host keys, 172, 175
host numbers, 17
-host option (route), 50
HOST suboption (xinetd), 166
host tool, 91
HostAP tool, 298, 300-303, 306
hostap_cs.conf file, 302
hostcvt tool (BIND), 91
hostlist, 164
hostname
      A record and, 81
      access database and, 218
      canonical, 75, 80, 81, 82
      chap-secrets file, 110
      dot and, 164n
      FEATURE macro and, 207
      FQDNs and, 203
      genericstable database and, 216
      hostlist and, 164
      IP addresses and, 67, 81, 103
      IP masquerade and, 207
      localhost, 51, 52
      mapping, 79, 82
      networks file and, 50n
      scp program and, 177
      setting, 44
      uniqueness of, 73
      xinetd and, 165
hostname command, 44
hostname option (nslookup), 89
hostname resolution
      defined, 8
      local nameservers and, 71
      nsswitch.conf and, 67
      overview, 27
      pppd and, 98
      TCP/IP networking and, 48-50
HostnameLookups option (Apache), 248
hosts
      access database and, 218
      adding, 93
      broadcasting and, 19
      communications and, 5
      defined, 1
      DHCP lease and, 47
      eavesdropping and, 122
      filtering and, 122
      firewalls and, 122
      as gateways, 7, 22
      IP addresses and, 8, 20, 45
      IP masquerade and, 156
      MAC addresses, 48
      mail and, 183, 184
      names for, 70, 75
      ports on, 9
      relay-domains file and, 214
      remote login to, 176
      security and, 163
      serial communications and, 29
      sizes of, 17
      spoofing and, 121
      thin Ethernet and, 4
      trusted, 163
      updating files for, 27
      zones and, 74
hosts database, 67
hosts: dns files, 71
hosts file
      backup host table in, 71
      configuring gateways and, 55
      hostcvt tool and, 91
      ifconfig and, 51
      nameservers and, 69
      writing, 48-50
hosts.allow file, 163
hosts.deny file, 163
hoststat command, 230, 231
HostStatusDirectory option, 230
HOSTS.TXT database, 27
HTTP, 123, 124, 148
httpd -l command, 255
httpd.conf file, 247, 250-252, 255
hub-and-spoke model, 298
hubs, active, 4
Hunt, Craig, 16, 199
hwaddr argument (arp), 64
HylaFAX software, 196
hyphen (-), 102, 110

I[ Top ]
-i built-in match (iptables), 138
-I subcommand option (iptables), 136
IANA (Internet Assigned Numbers Authority), 45, 233, 234
IBM, 5, 220, 266
ICMP (Internet Control Message Protocol)
      IP accounting and, 150, 151
      IP filtering and, 124
      iptables matches, 139
      netstat options and, 61
      TCP/IP and, 26-28
      traceroute and, 63
--icmp-type match option (iptables), 139
identity file, 174, 175
identity.pub file, 174, 178
idle option (pppd), 115
IEEE (Institute of Electrical and Electronics Engineers), 295, 296
IETF (Internet Engineering Task Force), 10, 267
if argument (route), 50
iface argument (ip-up), 105
ifconfig command
      bridging interface and, 306
      compatibility considerations, 52
      Ethernet interfaces, 53
      interface configuration and, 50
      IPv6 and, 237
      multicast support, 46
      network devices and, 30
      overview, 57-60
      PPPoE clients and, 118
IMAP (Internet Message Access Protocol)
      aliases and, 217
      choosing, 259-263
      Cyrus, 263-265
      email and, 180
      POP and, 258, 259
      purpose, 258
imapd.alert file, 261
imapd.conf file, 264
in-addr.arpa domain, 82
include option (Apache), 247
indefinite tokens, 200
inetd daemon, 160-163, 227, 267
inetd.conf file
      disabling r* commands, 171
      finger daemon, 163
      IMAP and, 260, 262
      overview, 161-162
      Samba in, 268
      SWAT and, 276
inetOrgPerson schema, 279
info top-level domain, 72
infrastructure mode, 297, 298, 303
--in-interface built-in match (iptables), 138
init command, 40
inittab file, 40
INPUT hook point (iptables)
      chains and, 127
      filter table and, 131, 134
      functionality, 129
      MAC match option, 139
      mangle table and, 131
input redirection (<), 37
--insert subcommand option (iptables), 136
install-cf command (Build), 210
installing
      Apache considerations, 248
      LDAP libraries, 286
      sendmail, 186-192
      ssh tools, 171-178
      UW IMAP, 259-261
instances option (xinetd), 165
Institute of Electrical and Electronics Engineers (IEEE), 295, 296
interfaces
      bind, 270
      bridging and, 306, 307
      configuring aliases for, 57
      defined, 16
      displaying netstat statistics, 62
      Ethernet, 16, 52-54
      GTK+-style, 291
      incompatible changes and, 169
      IP and, 50n
      IPv6 and, 237, 238
      packets and, 18
      packet-switching and, 26
      PPP, 57
      procmail argument (MAILER) and, 196
      promiscuous mode, 59
      Samba and, 270
      (see also loopback interface; network interfaces)
interference, 305
internal keyword (inetd.conf), 162
internal routing protocols, 25
internal services, 161
International Standards Organization (ISO), 96
Internet
      ARPANET and, 2
      dangers of, 119
      estimated users, 233
      expense of connections, 154
      growth of, 29
      HOSTS.TXT database, 27
      IP masquerade and, 155, 156, 157
      Linux documentation available, xii
      mail routing on, 184-185
      PPP links, 98
      prevalence of, ix
      RFC 822 and, 179, 183
      security considerations, 116
Internet Assigned Numbers Authority (IANA), 45, 233, 234
Internet Control Message Protocol (see ICMP)
Internet Daemon (see inetd daemon)
Internet Engineering Task Force (IETF), 10, 267
Internet Message Access Protocol (see IMAP)
Internet Protocol Control Protocol (IPCP), 97, 98, 102
Internet Protocol (see IP)
internetworking, 7
interoperability, 278
      (see also Samba)
interrupts, UART chips and, 34
intranets, 18
IP accounting, 11, 146-152
IP addresses
      access database and, 218
      ARP table and, 64
      assigning, 8, 44, 45
      binding, 247
      bridging and, 307
      choosing, 102, 104
      clearing, 306
      DHCP and, 45-48
      DNS and, 75, 94
      dotted quad notation, 8, 17, 110
      DSL modems and, 116
      end points and, 9
      finding, 8
      fixed, 47
      HostAP driver and, 303
      hostlist and, 164
      hostnames and, 81
      ifconfig and, 58
      interfaces and, 16
      IP accounting by, 147, 148
      IP masquerading and, 155
      IPv4 problems, 234
      IPv6 and, 235, 236
      looking up, 67
      mapping, 27, 82
      MTAs and, 184
      NAT and, 159, 234
      nslookup and, 89
      pap-secrets file and, 111
      Samba and, 276
      scarcity of, 154, 233
      TCP/IP and, 17-26
      virtual hosting, 57
      xinetd and, 165
IP Alias, 57
IP filtering
      example, 126
      IP masquerade and, 157
      iptables and, 129, 130, 134
      overview, 124-125
IP firewalling, 11, 125
IP forwarding, 55, 152n
IP (Internet Protocol)
      choosing gateways, 24-26
      configuration options, 102-105
      Frame Relay and, 5
      interfaces and, 50n
      iptables matches, 137
      networks, 20, 21
      overview, 6-8
      tunneling, 11
      virtual hosting, 250, 251
IP masquerade
      configuring, 157, 158
      example, 126
      hostnames and, 207
      IP firewalling and, 125
      kernel and, 157
      nameserver lookups and, 158
      NAT and, 154
      Net-4 and, 11
      overview, 156, 157
IP Multicast service, 17
ipchains command, 125, 134, 147
ipchains.o module, 134
ip_conntrack_ftp module, 157
IPCP (Internet Protocol Control Protocol), 97, 98, 102
ipcp-accept-local option (pppd), 103n
ipcp-accept-remote option (pppd), 103n
ipfwadm interface, 125, 134
ipfwadm.o module, 134
ip_nat_ftp.o module, 157
IPSec, 236
iptables command
      built-in matches, 137-141
      concepts, 127-133
      IP accounting and, 146, 147
      IP accounting by service port, 148
      IP masquerade and, 157, 158
      netfilter and, 134
      OpenLDAP and, 293
      options for, 134
      overview, 125-127
      resetting counters, 151
      rules and, 123, 152, 159
      security and, 121
      subcommands, 136, 137
      using, 134-135
ip_tables.o module, 134
ip-up command, 104, 105, 114
iputils package, 237
IPv4 standard
      addressing and, 8
      match options, 137
      OpenSSH and, 242
      problems with, 233, 234
      tunnel brokers and, 238
IPv6 standard
      AAAA record and, 81
      addresses with, 8, 235, 236
      advantages, 236
      applications and, 240-242
      configuration, 236-238
      troubleshooting, 242-243
      tunnel brokers and, ??-240
      xinetd and, 165
IPX, 11, 96
IPXCP, 97
irq option (ifconfig), 59
irq parameter (setserial), 35
ISDN, Net-4 and, 11
ISO (International Standards Organization), 96
ISO-3166, 73
iwconfig tool, 300, 303, 304
iwlist program, 300
iwpriv program, 300, 304, 305
iwspy program, 300
ixon flag (stty), 38

J[ Top ]
-j MASQUERADE option (iptables), 157
-j option (iptables), 135, 147
-j SNAT option (iptables), 157
Java applets, 291
--jump option (iptables), 135

K[ Top ]
K command (sendmail), 198, 199
kdebug option (pppd), 112
KeepAlive option (Apache), 249
KeepAliveTimeout option (Apache), 249
Kerberos authentication, 60, 264, 280
kermit terminal program, 29
kernel
      access control and, 31
      ARP tables, 63, 65
      debugging, 112
      domainname command, 44
      HostAP and, 301
      ICMP and, 26
      ifconfig command and, 50
      initializing, 42
      interfaces and, 16
      IP accounting and, 146
      IP firewall and, 123, 133, 134
      IP forwarding and, 55
      IP masquerade and, 157
      IPv6 and, 236, 237, 243
      loadable kernel module and, 299
      location of source code, 301
      MTU and, 106
      netfilter and, 119
      PPP and, 30, 97
      /proc filesystem and, 43
      serial ports and, 34
key ring, 187, 188, 189
KeyFile entry (httpd.conf), 256
keys (see private keys; public keys)
Kim, Gene, 15
klogd daemon, 112
known_hosts file, 174, 176
Krieger, Markus, 276

L[ Top ]
-l argument (ssh), 176
-L subcommand option (iptables), 136, 158
LANs (Local Area Networks)
      IP masquerading and, 155
      nameservers and, 71
      prevalence of, 154
      routing tables and, 25
      wireless networking and, 295
LCP (Link Control Protocol)
      overview, 105-107
      PPP and, 96
      pppd and, 98, 108
lcp-echo-failure option (pppd), 107
lcp-echo-interval option (pppd), 107
LDAP Data Interchange files (LDIF), 283-285
LDAP (Lightweight Directory Access Protocol)
      GUI and, 291
      overview, 278-279
      sendmail and, 190
      (see also OpenLDAP)
ldapadd utility, 283
ldapsearch command, 283, 285, 288
LDIF (LDAP Data Interchange files), 283-285
less than (<) sign (sendmail), 202
libc library, 27, 67
Libes, Don, 100
Lightweight Directory Access Protocol (see LDAP)
line discipline, 30
--line-numbers option (iptables), 135
Link Control Protocol (see LCP)
link-local address, 235, 238
Linux
      documentation available, xii
      getting the code, 12
      mailing lists, xiii
      obtaining, xiv
      platforms supported, ix
      Usenet newsgroups, xiii
      user groups, xiv
Linux Documentation Project, xii
Linux File System Standard Group (FSSTND), xv, 32
Linux Journal, xiii
Linux Magazine, xiii
Linux Standard Base, xv
Linux Systems Labs, xii
Linux Wireless Extension Tools, 300
linux.m4 file, 204
linux-wlan-ng driver, 300
--list subcommand option (iptables), 136
Listen option (Apache), 247
listening
      IPv6 cautions, 240, 241
      OpenLDAP and, 287
      OpenSSH and, 242
      ports and, 10
      Samba and, 271
      slapd program and, 282
      testing, 290
Liu, Cricket, 67
LKM (loadable kernel module), 299
lnp option (IMAP), 260
load printers option (printcap), 275
loadable kernel module (LKM), 299
loadavg file, 43
Local Area Networks (see LANs)
local argument (MAILER macro), 196
LOCAL keyword, 164
local mailer (MAILER macro), 196, 204
local_addr option
      ip-up, 105
      pppd, 103
LOCAL_CONFIG macro (sendmail), 197, 198
LOCAL_DOMAIN macro (sendmail), 213
localhost hostname, 51, 52
local-host-names file, 207, 211, 212-214
LOCAL_NET_CONFIG macro (sendmail), 197, 202
LOCAL_RULE_n macro (sendmail), 197
LOCAL_RULESET macro (sendmail), 197
lock files, 31, 32
lock keyword (pppd), 99
log file command (Samba), 272
log level command (Samba), 272
LogFormat option (Apache), 248
logins
      anonymous, 261
      PAP and, 108
      pppd and, 100
      remote, 170-178
      serial devices and, 38-41
LogLevel option (Apache), 248
log_on_failure option (xinetd), 166
log_on_success option (xinetd), 166
log_type option (xinetd), 165
Longyear, Al, 97
loopback address, 18
loopback interface
      defined, 18
      example, 24
      gated and, 26
      IP address and, 44
      overview, 51-52
      Samba and, 270
lowercase, sendmail and, 193
lpr command (BSD), 273
lsmod command, 243

M[ Top ]
=M command (sendmail), 223
M command (sendmail), 198
M field (mailstats), 229
M flag (netstat), 61
-M option (iptables), 135
-m option (iptables), 132, 135
m4 macro processor program
      Build utility and, 190
      hoststat command and, 230
      lowercase and, 193
      purpose, 186
      sendmail.cf file and, 192, 209
      virtusertable feature and, 222
MAC (Media Access Controller) addresses
      filtering, 303, 304
      fixed IP addresses and, 47
      HostAP and, 304, 305
      iptables and, 132, 138
      IPv6 and, 235, 238
      wireless networks and, 299
maccmd command, 304, 305
Mackaras, Paul, 97
--mac-source match option (iptables), 139
mail body, 180
mail domains, 183
mail exchangers, 82, 179, 184
      (see also electronic mail)
mail header
      composition of, 181
      defined, 180
      sendmail and, 199
      setting maximum length, 206
mail spool, 228
mail transfer agents (MTAs), 179
mail transport agents (MTAs), 182, 184
mail user agents (MUAs), 182
mail11 argument (MAILER macro), 196
mailboxes
      alternate formats, 261
      IMAP and, 261
      transport and, 179, 181, 183
Mailer field (mailstats), 230
MAILER macro (sendmail)
      mailers and, 204, 220
      overview, 196
mailertable database, 220, 221
mailertable feature, 220
mailing lists
      Linux, xiii
      PPP and, 97
      security and, 15
      sendmail-announce, 186
mailq command, 228
mailstats command, 229, 230
make command, 209, 247, 281
make depend command, 281
make install command, 247, 255
make test command, 281
Makefile
      OpenLDAP and, 281
      path options for OpenSSL, 262
      sendmail and, 209
      UW-IMAP and, 259
makemap command, 216
Malinen, Jouni, 300
managed mode, 297
Mandrake, 267
mangle table (iptables), 131
mangling, 123, 157
man-in-the-middle attack, 172
Mantin, Itsik, 296
/map command (sendmail), 223
mapping
      addresses, 159
      genericstable database and, 217
      hostnames, 27, 79
      IP addresses, 19, 82
      RPC and, 169, 170
MASQUERADE target (iptables), 157, 158
master files
      domains and, 79
      resource records and, 80-83
      writing, 84-87
--match option (iptables), 132, 135
max log size directive (Samba), 272
MaxClients option (Apache), 249
MaxHeadersLength option (sendmail.cf), 206
Maximum Receive Unit (MRU), 96, 105, 106
Maximum Transfer Unit (MTU), 16, 106, 149
Maximum Transmission Unit (MTU), 59
MaxKeepAliveRequests option (Apache), 249
max-lease-time option (DHCP), 47
MaxSpareServers option (Apache), 249
Media Access Controller addresses (see MAC addresses)
meminfo file, 43
mesg command, 113
Message-ID: field (mail header), 182
metasymbols, 200-202
metric option (ifconfig), 59
metric value, 26, 59
mgetty program, 39-41, 112, 113
Microsoft Windows, 266, 273
migrage_common.ph script, 287
migrate_all_online.sh script, 287
migration tools, 287
mil top-level domain, 72
MIME (Multipurpose Internet Mail Extensions), 180
minicom program, 29, 99
minimum field (SOA RR), 81
MinSpareServers option (Apache), 249
minus sign (-), 37, 58
Mockaptris, Paul, 28
mod_access module (Apache), 246
mod_actions module (Apache), 246
mod_alias module (Apache), 245
mod_asis module (Apache), 246
mod_auth module (Apache), 246
mod_auth_anon module (Apache), 246
mod_auth_db module (Apache), 246
mod_auth_dbm module (Apache), 246
mod_autoindex module (Apache), 245
mod_cern_meta module (Apache), 246
mod_cgi module (Apache), 246
mod_digest module (Apache), 246
mod_dir module (Apache), 245
modem keyword (pppd), 101
modem option (pppd), 113
modems
      abort messages, 102
      ATZ command and, 101
      demand dialing, 114, 115
      getty program and, 38
      mgetty program and, 112
      PPP servers and, 114
      pppd options and, 113
      software for, 29-30
      XOFF characters and, 105
mod_env module (Apache), 245
mod_example module (Apache), 246
mod_expires module (Apache), 246
mod_headers module (Apache), 246
mod_imap module (Apache), 246
mod_include module (Apache), 246
mod_info module (Apache), 246
mod_log_agent module (Apache), 246
mod_log_config module (Apache), 246
mod_log_referer module (Apache), 246
mod_mime module (Apache), 245
mod_mime_magic module (Apache), 245
mod_mmap_static module (Apache), 246
mod_negotiation module (Apache), 245
modprobe command, 134, 237, 302
--modprobe option (iptables), 135
mod_proxy module (Apache), 246
mod_rewrite module (Apache), 245
mod_setenvif module (Apache), 245
mod_so module (Apache), 246
mod_spelling module (Apache), 245
mod_ssl, 252-255
mod_status module (Apache), 246
mod_unique_id module (Apache), 245
mod_userdir module (Apache), 245
mod_usertrack module (Apache), 246
MODVERSIONS option (LKM), 299
MRU (Maximum Receive Unit), 96, 105, 106
mru option (pppd), 106
msgsdis field (mailstats), 230
msgsfr field (mailstats), 229
msgsreg field (mailstats), 230
msgsto field (mailstats), 230
--mss match option (iptables), 140
MTAs (mail transfer agents), 179
MTAs (mail transport agents), 182, 184
MTU (Maximum Transfer Unit), 16, 106, 149
MTU (Maximum Transmission Unit), 59
mtu option (ifconfig), 59
MUAs (mail user agents), 182
multicast addresses, 60
MULTICAST option (ifconfig), 47
Multipurpose Internet Mail Extensions (MIME), 180
mutt MUA, 182
/mx command (sendmail), 223
MX record
      bestmx_is_local feature and, 214
      overview, 82
      preferences and, 184
      querying for, 90
      sendmail test mode commands, 223
MySQL BDB, 280
MySQL service, 18

N[ Top ]
N flag (stty), 38
-N option
      iptables, 136
      ssh-keygen, 172
-n option (iptables), 135
name option
      dig, 88
      pppd, 111
name resolution, DNS and, 28, 74-75
name top-level domain, 72
named program, 66
named.conf file, 77-79, 83
nameserver option
      dig, 87
      resolv.conf, 69
nameservers
      DNS and, 74, 75, 98
      handling lookups, 158, 159
      hosts file and, 69
      LANs and, 71
      nslookup and, 89
      resolv.conf and, 69-71
      root, 90
      serial number and, 80
      verifying setup of, 87, 88
namespace, 73, 77
naming conventions, LDAP and, 279
NAT (Network Address Translation)
      address scarcity and, 233
      defined, 123
      IP addresses and, 45
      IP firewalling and, 125
      IP masquerade and, 154
      iptables and, 121, 127, 134
      netfilter and, 159
      overview, 234, 235
      spoofing and, 121
nat table (iptables), 131, 134
NCP (Network Control Protocol), 96
net directory, 43
-net option (route), 50, 53
net top-level domain, 72
Net-2, 11
Net-3, 11
Net-4, 11, 12
netfilter kernel module
      access control and, 301
      backwards compatibility with, 134
      firewalls and, 243
      IP masquerade and, 157
      kernel and, 119
      loading, 134
      NAT and, 159
      overview, 125-127
      packet processing and, 123
netmask option (ifconfig), 58
netmasks, 21, 25, 164, 234
NetRom protocol, 6, 11
netstat command
      Apache web server and, 241
      checking interface configuration, 54
      checking ports and, 120
      IMAP and, 260
      IPv6 and, 237
      overview, 60-63
      testing SSL availability, 290
net-tools package, 57, 237
Network Address Translation (see NAT)
Network Control Protocol (NCP), 96
Network File System (NFS), 169
Network Information Center (NIC), 17, 27, 73
network interface card (NIC), 4
network interfaces
      configuring, 50n
      gated and, 26
      scripts and, 42
      TCP/IP, 16
network layer
      denial of service and, 122
      ebtables command and, 126
      IP filtering and, 124
      protocols, 6, 45
network numbers, 17, 21, 45
networking
      access database and, 218
      broadcast, 56
      choke points, 122
      congested, 55
      DHCP lease and, 45
      email and, 179
      gateways and, 22-24
      global village and, ix
      history, 1
      IP masquerade and, 156
      IPv6 and, 236
      Linux, 12-13
      perimeter, 122
      system maintenance, 13-15
      TCP/IP networks, 2-11
      unauthorized access, 120
      (see also wireless networks)
networks database, 67
networks file, 50, 53
newaliases command, 212
--new-chain subcommand option (iptables), 136
newsgroups
      DNS, 67
      PPP and, 97
      Usenet, xiii
NFS (Network File System), 169
NIC (Network Information Center), 17, 27, 73
NIC (network interface card), 4
nice configuration option (xinetd), 167
NIS domain, 44
nmbd process, 277
NO CARRIER message, 102
NOARP flag (ifconfig), 59
noauth option (pppd), 107
noipdefault option (pppd), 103
nopwd option (IMAP), 260
notfound option (nsswitch.conf), 68
Novell, 11, 12n, 96
Novell NCP (NetWare Core Protocol), 11
NS record
      as glue record, 77
      nslookup and, 90
      purpose, 82
      type option and, 80
nslint tool, 91
nslookup tool, 88-91
NSS library (LDAP), 286, 288
nss_ldap package, 286
nsswitch.conf file, 67-69, 288
NULL character (ASCII), 106
--numeric option (iptables), 135

O[ Top ]
-o built-in match (iptables), 138
O command (sendmail), 198
octets, 17, 59
OK action (access rule), 218
100-baseT, 4
1000-baseT, 4
only_from option (xinetd), 165
OpenBSD project, 171n
OpenLDAP
      compiling, 281
      configuring server, 282
      dependencies with, 280
      GUI browsers, 291
      obtaining, 280
      overview, 278
      running, 282-285
      SSL and, 289-291
      troubleshooting, 291-293
      using, 285-289
OpenLDAP BDB (backend database), 280
openldap.conf file, 288
OpenSSH project, 171, 240, 242
OpenSSL
      Apache web servers and, 252-256
      certificates and, 290
      generating SSL certificates, 252, 253
      IMAP and, 260, 261-263
      OpenLDAP and, 280
      security considerations, 15
      SWAT and, 276
OperatorChars option (sendmail.cf), 200
option domain-name option (DHCP), 47
option domain-name-servers option (DHCP), 47
option router command, 47
options file
      auth option, 109
      demand dialing and, 114
      mgetty program and, 113
      overview, 99
      security considerations, 107
org top-level domain, 72
Organization: field (mail header), 182
origin, 79
origin field (SOA RR), 80
Orinico_cs drivers, 299, 300
OSTYPE command (generic-linux.mc), 204
OSTYPE file, 205
OSTYPE macro (sendmail), 194
--out-interface built-in match (iptables), 138
Outlook mail reader, 181
OUTPUT hook point (iptables)
      chains and, 127
      filter table and, 131
      functionality, 129
      iptables and, 134
      mangle table and, 131
      nat table and, 131

P[ Top ]
-p built-in match (iptables), 138
P command (sendmail), 198
-P subcommand option (iptables), 136
Packet Assembler Disassembler (PAD), 5
packet filtering (see IP filtering)
packet flooding, 150
packet mangling, 123, 157
packet radio, 6, 59
packet sniffing, 122
packets
      chains and, 131
      as datagrams, 2, 7
      encapsulation of, 5
      Ethernet and, 4
      Ethernet maximum size, 53
      firewall packet logging and, 133n
      flow of, 127-129
      fragmenting, 149, 150
      ICMP, 150
      interfaces and, 16, 18
      IPv6 and, 236
      netfilter subsystem and, 123
      rules and, 132
packet-switching
      gateways and, 22, 55
      interfaces and, 26
      protocols for, 2
      support for, 5
PAD (Packet Assembler Disassembler), 5
PAM library (LDAP), 286, 288
pam_ldap package, 286
PAP (Password Authentication Protocol)
      authorization and, 96
      CHAP and, 108, 109
      mgetty program and, 113
      pap-secrets file, 111
      PPP and, 108, 113
      pppd and, 97, 99
pap-secrets file, 109, 111
PARANOID keyword, 164
parenb flag (stty), 38
parodd flag (stty), 38
/parse command (sendmail), 223
passphrases, 175, 252, 253
passwd command, 113
passwd file, 112, 113, 162
Password Authentication Protocol (see PAP)
passwords
      chat script and, 101n
      Cyrus IMAP and, 264
      eavesdropping and, 122
      login procedure and, 108
      PPPoE client and, 118
      remote login and, 171
      Samba and, 269, 277
      security and, 14
      ssh command and, 176, 178
      TFTP and, 162
patch lists, 120
PCI, 301
PCMCIA, 301
pcmcia-cs, 299
PDAs, 233
PDC (Primary Domain Controller), 266
PEM pass phrase, 252, 253
perimeter networks, 122
Perkins, Drew, 97
permissions, 256
persist option (pppd), 115
persistent dialing, 115
PGP keys (sendmail), 187
PGPKEYS file, 188, 189n
phquery argument (MAILER macro), 196
pid (process ID), 31
PID suboption (xinetd), 166
pine MUA, 181, 182
ping command, 51, 117
ping flooding, 150
ping6 tool, 237
PKI environment, 278
PLIP, 11, 56, 59
plipconfig tool, 57
plus sign (+), 94, 256
PLX, 301
pointopoint option (ifconfig), 59
point-to-point links, 56
Point-to-Point Protocol (see PPP)
policy, chains and, 131
--policy subcommand option (iptables), 136
pop argument (MAILER macro), 196
POP (Post Office Protocol)
      aliases and, 217
      IMAP and, 258, 259
      MAILER macro and, 196
port field (services), 168
port parameter (setserial), 35
portmapper daemon, 52n, 170
ports
      accounting services by, 148-150
      binding, 247
      daemons and, 160
      ICMP and, 150
      LDAP and, 282
      netstat command and, 120
      outgoing connections and, 63n
      overview, 10
      Samba and, 268, 276
      services and, 167
      TCP and, 9
      troubleshooting, 293
Post Office Protocol (see POP)
POSTROUTING hook point (iptables)
      chains and, 127
      functionality, 129
      mangle table and, 131
      nat table and, 131, 134
pound sign (#), 67, 78, 99, 171, 192
PPP (Point-to-Point Protocol)
      advanced configurations, 112-116
      authentication with, 108-111
      debugging and, 112
      escape characters for, 105
      interfaces, 57
      interfaces and, 16
      IP accounting by service port, 148
      IP configuration options, 102-105
      kernel and, 30
      Linux and, x
      Net-4 and, 11
      overview, 96, 97
      security considerations, 107, 108
      serial communications and, 30
      SLIP and, 8
pppd daemon
      authentication and, 109
      chap-secrets file and, 109, 110
      chat and, 100-102
      demand dialing, 114
      IPCP options and, 102
      LCP and, 108
      options files, 99
      pap-secrets file, 111
      persistent dialing and, 115
      purpose, 97
      running, 98, 99
      security considerations, 107
      as server, 112, 114
ppp-log file, 112
PPPoE (PPP over Ethernet)
      connections used, 30
      DSL and, 96
      options for, 116-118
preference field (MX RR), 82
-prefix= option (make install), 247
PREPENDDEF macro (Build), 190
PREROUTING hook point (iptables)
      chains and, 127
      functionality, 129
      MAC match option, 139
      mangle table and, 131
      nat table and, 131, 134
Primary Domain Controller (PDC), 266
primary option (named.conf), 79
primary servers, 75, 82
printcap file, 274, 275
printing, Samba and, 273-275
Prism chipsets, 296, 297, 300
private keys
      defined, 172
      ssh clients and, 174
      ssh-keygen command and, 175
      SWAT and, 276
/proc filesystem (procfs)
      ARP tables, 63, 65
      assigning IP addresses, 44, 45
      creating subnets, 48
      DHCP and, 45-48
      Ethernet interfaces, 52-54
      gateways and, 54, 55
      hostname resolution, 48-50
      ifconfig command and, 57-60
      installing tools, 43
      interfaces and, 50n
      IP Alias, 57
      loopback interface, 51-52
      netstat command, 60-63
      PPP interface, 57
      setting hostnames, 44
      traceroute tool and, 63
process ID (pid), 31
procfs (see /proc filesystem)
procmail argument (MAILER macro), 196
prog mailer (MAILER macro), 196, 204
program numbers, 169
promisc option (ifconfig), 59, 60
promiscuous mode
      eavesdropping and, 122
      ifconfig and, 59, 152
      iptables and, 129
      iwpriv program and, 300
promiscuous_relay feature, 215
--protocol built-in match (iptables), 138
protocol field
      inetd, 161
      services, 168
protocols
      for amateur radio, 6
      defined, 1
      encryption and, 4
      IP accounting by, 151
      serial, 8
      (see also specific protocols)
protocols file, 167-169
proxy ARP, 56, 64, 65, 104
proxy servers, 121, 122, 124
proxyarp option (pppd), 104
ps command, 101
pseudo-domains, 206, 220
PTR record, 80, 82, 91
public command (Samba), 271
Public Key Cryptography, 171
public keys
      authorized_keys file and, 178
      defined, 172
      fingerprints, 176
      ssh clients and, 174, 176
      ssh-keygen command and, 175
purgestat command, 231

Q[ Top ]
-q10m argument (sendmail), 228
QoS (Quality of Service), 6, 236
qpage argument (MAILER macro), 196
Quality of Service (QoS), 6, 236
querying
      dig tool and, 88
      DNS servers, 87
      host tool and, 91
      IP addresses, 19, 20, 89
      LDAP server and, 283, 288, 289
      nameservers and, 71, 98
      recursive, 78
      for root domain, 74
      for root nameservers, 90
      servers handling mail, 88
      services, 68
QUEUE target (iptables), 133
QuickPage mailer, 196
/quit command (sendmail), 223
quotation marks (") (ssh), 177

R[ Top ]
R command (sendmail), 198, 199, 200
R configuration command (sendmail), 199
-R subcommand option (iptables), 136
random key generator, 172
RARP (Reverse Address Resolution Protocol), 20
rc.inet1 script, 42
rc.inet2 script, 42
rcp command, 170
rc.serial script, 35, 36
rdata field (resource record), 80
RDN (Relative Distinguished Names), 279
Received: field (mail header), 182
Red Hat
      bridging networks, 306
      IMAP and, 260, 262
      kernel source code and, 301
      Samba and, 267
      yum utility, 120
Redirect message (ICMP), 26, 27, 61
refresh field (SOA RR), 80
REJECT action (access rule), 218
REJECT target (iptables), 132
Relative Distinguished Names (RDN), 279
RELAY action (access rule), 218
relay mailer (MAILER macro), 196, 197, 204, 220
RELAY_DOMAIN command, 214
relay-domains database, 211
relay-domains file
      access database and, 217
      configuring, 208, 214
      overview, 214, 215
relay_entire_domain feature, 215
relay_local_from feature, 215
remote login, 170-178
Remote Procedure Call (RPC), 169, 170
remote_addr option
      ip-up, 105
      pppd, 103
remotename keyword (pppd), 111
--rename-chain subcommand option (iptables), 136
--replace subcommand option (iptables), 136
Reply-To: field (mail header), 182
Request to Send (RTS), 33
requested command, 172
reset command, 101
resolv.conf file
      DHCP and, 46
      dig tool and, 87
      nameserver lookups using, 69-71
      PPPoE clients, 117
resolver library, 27, 67-71
resolvers
      djbdns, 66, 92-93
      nsswitch.conf and, 68, 69
      pppd and, 98
      resolv.conf, 69-71
      resolver library, 67
      resource records and, 79
      robustness of, 71
resource records (RRs), 75, 79-83
respawn option (mgetty), 40
restart option (apachectl), 250
retry field (SOA RR), 81
return option (nsswitch.conf), 68
RETURN target (iptables), 131, 133
Reverse Address Resolution Protocol (RARP), 20
rewrite rules
      example, 202, 203
      left side, 200, 201
      mailers and, 220
      right side, 200, 202
      sendmail and, 199
rexec command, 15, 171
rexec service (BSD), 120
RFC 821, 183, 185, 219
RFC 822
      as common denominator, 180
      FidoNet and, 184
      header format, 180
      Internet and, 179, 183
RFC 974, 185
RFC 1123, 185
RFC 1179, 273
RFC 1341, 180
RFC 1437, 179n
RFC 1591, 138
RFC 1700, 10
RFC 1893, 219
RFC 1912, 78
RFC 1918, 18, 45
RFC 2251, 279
RFC 2253, 278
RFC 2849, 283
RFC 3232, 139
RFC 3501, 258
RING message, 39
RIP (Routing Information Protocol), 25, 26
rlogin command, 15, 170, 171
rlogin service (BSD), 120, 121
Roaring Penguin, 116
root account
      cron job output and, 13
      LDAP server and, 288
      ssh daemon and, 174
      troubleshooting Samba, 277
root domain, 71, 74
root nameservers, 90
root.hint file, 84
rootpw option (slapd.conf), 282
Rose protocol, 6, 11
route command
      building tables, 25
      compatibility considerations, 52
      displaying information, 25
      Ethernet interfaces and, 53
      interface configuration and, 50
      PPP links and, 104, 105
routing
      advanced policy, 11
      defined, 7
      DNAT and, 156
      email and, 184-185
      Ethernet interfaces and, 53
      fragmentation and, 149
      gateways and, 54
      ICMP and, 27
      IP addresses, 20-24
      IPv6 traffic, 238
      PPP links, 104-105
      PPP servers and, 114
      protocols for, 25
      strictness of rules for, 154
      TCP and, 9
Routing Information Protocol (RIP), 25, 26
routing tables
      initializing, 50
      metric value and, 26
      netstat command and, 60, 61
      overview, 24-26
      TCP/IP networking and, 43
rpc file, 169, 170
RPC (Remote Procedure Call), 169, 170
RRs (resource records), 75, 79-83
RS-232 standard, 33, 34
RSA keys, 172
rsh command, 15, 170, 171
RTM Internet worm, 163
RTS (Request to Send), 33
rules
      access database and, 218
      IP accounting and, 150
      IP masquerade and, 157
      iptables and, 132, 149
      mapping addresses, 159
      matches for, 126, 131
      sendmail and, 199, 200
      (see also rewrite rules)
RUNNING flag (ifconfig), 58
runq command, 228, 229
Russell, Paul, 125

S[ Top ]
-s built-in match (iptables), 138
=S command (sendmail), 223
S command (sendmail), 198, 199, 200
-s option (arp), 64
Samba
      access control, 270-272
      CIFS and, 266, 267
      configuring, 268-270
      interoperability and, 11
      logging with, 272
      obtaining, 267, 268
      printing with, 273-275
      troubleshooting, 277
Samba Web Administration Tool (SWAT), 276
SASL (Simple Authentication and Security Layer) package, 264, 265, 280
scp program (ssh), 170, 174, 177
scripts
      adsl-setup, 116
      adsl-start, 117
      chat, 100, 101
      expect, 100
      migrage_common.ph, 287
      migrate_all_online.sh, 287
      pppd and, 100
      TCP/IP networking and, 42
search lists, 70
search option (resolv.conf), 70
secondary servers, 75, 82
secrets database, 108
Secure Shell (SSH), 120, 156
security
      802.11b and, 296-307
      access database and, 208
      DNS cache and, 78
      enabling relaying and, 215
      finger service and, 162
      host lookups and, 70
      importance of, 119
      Internet and, 116
      IPv6 and, 236
      mail accounts and, 259
      passphrases and, 175
      PPP and, 107, 108
      relay-domains file and, 214
      RTM Internet worm and, 163
      Samba and, 269, 270
      sendmail and, 186
      ssh command and, 171, 176
      system maintenance and, 13-15
      wireless networking and, 4, 295
      xinetd and, 166
semicolon (;), 79
send strings, 100, 102
sendmail
      additional information, 231
      configuration files, 192-198
      creating a configuration, 203-210
      databases used, 210-222
      downloading source code, 187-190
      installing, 186-192
      overview, 179
      running, 227
      sendmail.cf, 198-203
      signing key fingerprints, 188
      testing configuration, 222-227
      tips and tricks, 228-231
sendmail mail daemon, 163
sendmail-announce mailing list, 186
sendmail.cf file
      building, 209, 210
      configuration language, 198-203
      define command and, 195
      editing, 186
      generic.m4 file and, 206
      LOCAL macro and, 197
      mailers and, 204
      StatusFile option, 230
      tuning, 192
sendmail.mc file
      comments, 192
      FEATURE macro and, 195
      m4 program and, 192
      sample, 203-204
      typical commands, 193-198
serial field (SOA RR), 80
Serial Line IP (SLIP), 8, 11, 59
serial ports/devices
      accessing, 30-34
      configuration utilities, 34-38
      login: prompt, 38-41
      mgetty program and, 113
      modem links, 29-30
      PAD and, 5
      PPP and, 97, 114
      pppd and, 99
server configuration option (xinetd), 167
server field (inetd), 162
Server Message Blocks (SMB), 266, 267
server_args configuration option (xinetd), 167
ServerRoot option (Apache), 248
servers
      Apache configuration options, 248
      authentication and, 96
servers (continued)
      dynamic addresses and, 103
      ports and, 10
      PPP, 112-114
      pppd as, 112
      proxy, 121, 122, 124
      RPC and, 169
      secrets database and, 108
      ucspi-tcp program, 92
      WAN IP addresses and, 116
      web, 156, 276
ServerSignature option (Apache), 249
ServerTokens option (Apache), 249
service field
      inetd, 161
      services, 168
servicelist, 164
services
      accounting by ports, 148-150
      action items, 68
      denial of service attacks and, 121
      exploiting weaknesses in, 123
      finger, 162
      internal, 161
      port numbers and, 167
      portmapper daemon and, 170
      query order, 68
      security and, 14
services file, 167-169, 276
set type command, 89
--set-counters option (iptables), 135
setserial command, 34-36
setuid program, 14, 107
seyon terminal program, 29
shadow file, 112
shadow passwords, 14, 162, 264
Shamir, Adi, 296
Shapiro, Greg, 204
shared directories, 271
shellcmd field (fingerd/tftpd), 164
SIGHUP signal, 276
signatures, 180n, 187, 189
silent option (pppd), 113
Simple Authentication and Security Layer (SASL) package, 264, 265, 280
Simple Mail Transfer Protocol (see SMTP)
single quotation mark ('), 194
site configuration, 190
site.config.m4 file, 190
site.linux.m4 file, 190
site-local address, 236, 238
site.post.m4 file, 190
skip_test parameter (setserial), 35
slapd program, 282
slapd.conf file, 282, 286, 292
Sleepycat Software, 280
SLIP (Serial Line IP), 8, 11, 59
slogin program (ssh), 174
slurpd program, 282
SMB (Server Message Blocks), 266, 267
smbclient program, 268
smb.conf file, 273, 275
smbd process, 277
smbmount utility, 269
smbpasswd utility, 269
smmsp user/group, 191
smtp mailer (MAILER macro), 196, 204, 220
SMTP (Simple Mail Transfer Protocol)
      Connect: tag field and, 218
      firewalls and, 123
      IP accounting by service port, 148
      MAILER macro and, 196
      remote delivery and, 183
      sendmail and, 203, 224, 225
smtp8 mailer (MAILER macro), 196, 197, 204, 220
SNAT (Source NAT), 154, 157, 159
SNAT target (iptables), 157, 159
snooping, Ethernet, 59
SOA record
      at sign in, 76
      fields in, 80, 81
      nslookup and, 89
      purpose, 76
      ttl and, 79
      type option and, 80
socket library, 11
sockets, 62, 160, 161
socket_type configuration option (xinetd), 167
software
      Apache web servers, 245-247
      bridging, 306
      communications, 29, 30
      security considerations, 14
      testing networking, 18
      troubleshooting wireless networks, 305
software field (HINFO RR), 83
--source built-in match (iptables), 138
Source NAT (SNAT), 154, 157, 159
--source-port match option (iptables), 140
spaces, 67, 79, 194
Spafford, Gene, 15
spd_hi parameter (setserial), 35
spd_normal parameter (setserial), 35
spd_vhi parameter (setserial), 35
Specialized Systems Consultants, Inc. (SSC), xii, xiii
speed argument (ip-up), 105
spoofing, 121, 176
--sport match option (iptables), 140
Spurgeon, Charles, 5n
--src built-in match (iptables), 138
SSC (Specialized Systems Consultants, Inc.), xii, xiii
ssh client, 172, 174-176
ssh command
      localhost and, 52
      remote hosts and, 170
      security and, 171
      using, 176-178
ssh daemon, 172-174
SSH protocol, 121, 172
ssh tools, 10, 15, 171-178
ssh_config file, 174
sshd_config file, 3, 242
ssh_host_key file, 172
ssh-keygen utility, 172, 175
SSL
      Apache and, 252
      certificates and, 252, 253
      named virtual hosting and, 251
      OpenLDAP and, 281, 289-291
      SWAT and, 276
      troubleshooting, 257, 293
SSLCertificateFile entry (httpd.conf), 256
SSLCERTS option (Makefile), 260
SSLDIR option (Makefile), 262
SSLEngine, 256
SSLINCLUDE option (Makefile), 262
SSLLIB option (Makefile), 262
SSLPATH option (Makefile), 260
start option (apachectl), 250
StartServers option (Apache), 249
startssl option (apachectl), 250
status option (apachectl), 250
StatusFile option (sendmail.cf), 230
stop option (apachectl), 250
stty command, 36-38, 113
Stubblefield, Adam, 296
stunnel tool, 276
subdomains, 71, 73
Subject: field (mail header), 182
submit.cf file, 210
subnet masks, 21, 234
subnetworks, 21, 22, 48
subscripts, 102
success option (nsswitch.conf), 68
Sun, Andrew, 96
Sun Microsystems, 169
super servers
      inetd, 160-163
      xinetd, 164-167
SuSE, 120, 262, 267
suucp mailer (MAILER macro), 196
svscan process, 93, 94
SWAT (Samba Web Administration Tool), 276
swatch tool, 272
--syn match option (iptables), 140
synchronous serial ports, 5, 6
syslog.conf, 101n, 112, 163
syslogd daemon, 112
system administration, 13-15
system configuration, IPv6 and, 236, 237
system log (syslog)
      bridging and, 306
      card identification and, 305
      HostAP driver and, 302
      logging with, 272
      Samba and, 273
      troubleshooting and, 291, 293

T[ Top ]
T command (sendmail), 198
-t option
      arp, 64
      iptables, 135
tab character, 67, 79, 199
--table option (iptables), 135
tables
      ARP, 63, 65
      iptables and, 126, 127, 130, 131
      mapping via, 27
tar command, 177
targets
      chains and, 131
      IP masquerade and, 158
      iptables and, 126, 132, 133, 159
TCP (Transmission Control Protocol)
      distinguishing connections, 10
      inetd.conf and, 161
      IP accounting and, 148, 151
      IP filtering and, 124
      iptables matches, 140
      overview, 8, 9
      ports and, 150
      RPC and, 169, 170
TCP (Transmission Control Protocol) (continued)
      tcpd and, 163
      ucspi-tcp program, 92
      Van Jacobson header compression, 97
tcpd access control facility, 163, 164
tcpdump tool, 59, 114
--tcp-flags match option (iptables), 140
TCP/IP networking
      ARP tables, 63, 65
      creating subnets, 48
      DHCP and, 45-48
      Ethernet interfaces, 52-54
      gateways and, 54, 55
      hostname resolution, 48-50
      ICMP and, 26-28
      ifconfig command and, 57-60
      installing tools, 43
      interfaces and, 16, 50n
      IP addresses, 17-26, 44, 45
      IP Alias, 57
      Linux and, x
      loopback interface, 51-52
      netstat command, 60-63
      overview, 2-11
      PPP interface, 57
      setting hostnames, 44
      SMTP and, 183
      socket library for, 11
      traceroute tool and, 63
      Unix and, 2
--tcp-option match option (iptables), 140
tcpwrappers, 270
teletype devices (see tty devices)
telnet, 105, 124
10-base2, 4
10-base5, 4
10-baseT, 4
Terminal Node Controller, 6
terminal programs, 29
testparm program, 268, 273, 277
tftp daemon, 162
tftp service, 164
TFTP (Trivial File Transfer Protocol), 14, 162
Thawte, 252
thick Ethernet, 3, 4
thin Ethernet, 3, 4
time to live (see ttl)
Timeout option
      Apache, 249
      chat, 102
tkrat MUA, 182
TLDs (top-level domains), 72, 73, 250
To: field (mail header), 181
To: tag field, 218
toggle-dtr keyword (mgetty), 40
Token Ring, 5, 11
tokens, 200, 202
top-level domains (TLDs), 72, 73
Torvalds, Linus, x
Tourrilhes, Jean, 300
Toxen, Bob, 121
tracepath6 tool, 237
traceroute tool, 63
traceroute6 tool, 237
TRAFFIC suboption (xinetd), 166
Transmission Control Protocol (see TCP)
tree structure, 278
tripwire tool, 15
Trivial File Transfer Protocol (TFTP), 14, 162
troubleshooting
      802.11b standard, 305-306
      Apache web servers, 256-257
      Cyrus IMAP, 265
      IPv6 and, 242-243
      OpenLDAP, 291-293
      Samba, 277
trusted hosts, 163
/try command (sendmail), 223, 227
tryagain option (nsswitch.conf), 69
/tryflags command (sendmail), 223, 227
Ts, Jay, 266
ttl field (resource record), 79
ttl (time to live)
      defined, 75
      resource records and, 79, 81
      SOA record and, 76
tty devices
      defined, 30
      opening, 31
      PPP servers and, 112
      stty command, 37
tunnels, 238-240, 276
twisted pair Ethernet, 3, 4
type field
      inetd, 161
      resource record, 80
type option (dig), 88

U[ Top ]
U flag (netstat), 61
UART chips, 34
uart parameter (setserial), 35
ucspi-tcp program, 92
UDP (User Datagram Protocol)
      inetd.conf and, 161
      IP accounting and, 148, 151
      IP filtering and, 124
      iptables matches, 139
      overview, 9
      ports and, 150
      RPC and, 169, 170
      tcpd and, 163
      traceroute and, 63
unavail option (nsswitch.conf), 69
undefine command (m4), 195
Unix
      Berkeley Socket Library, 10
      counting and, 31
      daemontools program, 92
      init command, 40
      kermit and, 29
      lpr command and, 273
      m4 program, 186
      networks and, ix
      sendmail and, 179
      socket library for, 11
      TCP/IP and, 2
      tty devices and, 30
UNKNOWN keyword, 164
up option (ifconfig), 58
uppercase, 193
URIs, 271, 288
Urlichs, Matthias, 12
USB, 301
use_ct_file feature, 219
use_cw_file feature, 211, 212
usehostname option (pppd), 111
usenet argument (MAILER macro), 196
Usenet newsgroups, xiii, 196
user accounts, 269, 277, 285
user configuration option (xinetd), 167
user database, 219
User Datagram Protocol (see UDP)
user field (inetd), 161
user ID, 191
useradd utility, 112n
username
      adding to classes, 207
      eavesdropping and, 122
      FEATURE macro and, 199
      genericstable database and, 216
      login procedure and, 108
      PPP servers and, 113
      PPPoE client and, 118
      remote login and, 171
uucico program, 99
uucp argument (MAILER macro), 196
UUCP environment, 180, 184, 196, 220
uucpdomain database, 220
uucpdomain feature, 220
UW IMAP, 259-261

V[ Top ]
V command (sendmail), 198
-v option
      chat, 101
      iptables, 135
-V subcommand option (iptables), 136
valid users option (Samba), 271
vampire taps, 4
Van Jacobson header compression, 97, 106
van Kempen, Fred, 11
variables, 191, 195
/var/lock directory, 32
--verbose option (iptables), 135
Verisign, 252
--version subcommand option (iptables), 137
VERSIONID macro
      generic-linux.mc, 204
      generic.m4, 206, 208
      linux.m4, 205
      sendmail, 193
versions
      OpenLDAP and, 280
      RPC and, 169
Virtual Brewery, 309
virtual hosting, 57
virtual terminals, 30, 38, 100
VirtualHost functionality (httpd.conf), 250-252, 255, 257
virtusertable database, 220, 221, 222
virtusertable feature, 221
VJ header compression (see Van Jacobson header compression)
Voice over IP, 236
VPNs, 296, 303
vulnerabilities
      BIND and, 92
      RTM Internet worm, 163
      security considerations and, 15

W[ Top ]
wait configuration option (xinetd), 167
wait field (inetd), 161
WANs, server addresses and, 116
WaveLAN cards, 297, 306
web browsers, 251, 291
web servers, 156, 276
      (see also Apache web servers)
WEP (Wired Equivalent Privacy)
      attacks on, 296
      HostAP and, 303, 304
      iwconfig tool and, 300
whitespace, 67
WiFi Protected Access (WPA), 295
wildcards, 110, 174, 283
Windows (Microsoft), 266, 273
WinModem, 34n
Wired Equivalent Privacy (see WEP)
wireless networks
      802.11b security concerns, 296-305
      acceptance of, 294
      bridging, 306-307
      history, 294, 295
      Linux and, 4
      standards, 295-296
      troubleshooting, 305-306
--with-inet6 option (xinetd), 165
--with-syslog option (Samba), 272
-with-tls option (OpenLDAP), 281, 289
working groups, 295
World Wide Web, 124, 148, 211
      (see also Internet)
WPA (WiFi Protected Access), 295
writable command (Samba), 271

X[ Top ]
X- field (mail header), 182
-x option (iptables), 135
-X subcommand option (iptables), 137
X terminals, 162
X.11, 29, 30
X.25 protocol, 5, 11, 96
X.400 standard, 179, 183, 184
x509 option (OpenSSL), 253
XDR (External Data Representation) format, 169
xinetd super server, 164-167
xinetd.conf file, 165, 263, 268, 276
XON/XOFF handshaking, 33, 105

Y[ Top ]
YaST Online Update (YOU) utility, 120
YOU (YaST Online Update) utility, 120
yum utility (Red Hat), 120

Z[ Top ]
-Z subcommand option (iptables), 137
--zero subcommand option (iptables), 137
zeroes, double-colon and, 235, 242
zone option (named.conf), 78
zones
      domains and, 73
      nameservers and, 74
      NS records and, 82
      RFC 1912, 78
      serial numbers and, 80
      SOA records and, 80