3 ndb \- Network database
6 The network database consists of files
7 describing machines known to the local
8 installation and machines known publicly.
9 The files comprise multi-line tuples made up of
10 attribute/value pairs of the form
14 Each line starting without white space starts a new tuple.
21 is the root of the database.
22 Other files are included in the
23 database if a tuple with an
24 attribute-value pair of attribute
26 and no value exists in
31 each pair with attribute
33 identifies a file to be included in the database. The files are searched
34 in the order they appear.
44 declares the database to be composed of the three files
51 is searched before the others.
54 may be included in the
56 to redefine its ordering.
58 Within tuples, pairs on the same line bind tighter than
59 pairs on different lines.
61 Programs search the database directly using the routines in
63 .\" or indirectly using
73 imposes structure on the otherwise flat database by using
74 knowledge specific to the network.
75 The internet is made up of networks which can be subnetted
76 multiple times. A network must have an
78 attribute and is uniquely identified by the values of its
84 is missing, the relevant Class A, B or C one is used.
86 A search for an attribute associated with a network or host starts
87 at the lowest level, the entry for the host or network itself,
88 and works its way up, bit by bit, looking at entries for nets/subnets
89 that include the network or host. The search ends when the attribute
91 For example, consider at the following entries:
94 ipnet=murray-hill ip=135.104.0.0 ipmask=255.255.0.0
96 ntp=ntp.cs.bell-labs.com
97 ipnet=plan9 ip=135.104.9.0 ipmask=255.255.255.0
98 ntp=oncore.cs.bell-labs.com
99 smtp=smtp1.cs.bell-labs.com
100 ip=135.104.9.6 sys=anna dom=anna.cs.bell-labs.com
101 smtp=smtp2.cs.bell-labs.com
108 which is in turn on the class B net
110 Assume that we're searching for
116 The search starts by looking for an entry with
118 We find the anna entry. Since it has an
119 .B smtp=smtp2.cs.bell-labs.com
121 we're done looking for that attribute.
122 To fulfill the NTP request, we continue by looking for networks
123 that include anna's IP address.
124 We lop off the right most one bit from anna's address and
129 Not finding one, we drop another bit and look for an
134 such an entry and it has the pair,
135 .BR ntp=oncore.cs.bell-labs.com ,
139 .\" can be made to perform such network aware
140 .\" searches by using metanames in the dialstring.
143 .\" followed by an attribute name.
145 .\" looks up the attribute relative to the system it is running
146 .\" on. Thus, with the above example, if a program called
149 .\" dial("tcp!$smtp!smtp", 0, 0, 0);
152 .\" the dial would connect to the SMTP port of
153 .\" .BR smtp2.cs.bell-labs.com .
155 A number of attributes are meaningful to programs and thus
173 file to download for initial bootstrap
176 Internet network name
179 Internet network mask
185 authentication server to be used
188 authentication domain. Plan 9 supports multiple authentication
189 domains. To specify an authentication server for a particular domain,
190 add a tuple containing both
194 attributes and values.
197 file server to be used
209 a TCP, UDP, or IL port number
212 a TCP service that can be called only by ports numbered
216 a protocol supported by a host.
221 adds onto any unrooted names when doing a search
222 There may be multiple
227 a DNS server to use (for DNS and DHCP)
230 an NTP server to use (for DHCP)
233 an SMTP server to use (for DHCP)
236 a time server to use (for DHCP)
239 a Windows name server (for DHCP)
242 mail exchanger (for DNS and DHCP)
245 start of area (for DNS)
251 .\" is used during authentication to decide who has the power to `speak for' other
256 A tuple for the CPU server, spindle.
260 dom=spindle.research.bell-labs.com
261 bootf=/mips/9powerboot
262 ip=135.104.117.32 ether=080069020677
266 Entries for the network
271 ipnet=mh-astro-net ip=135.104.0.0 ipmask=255.255.255.0
272 fs=bootes.research.bell-labs.com
273 ipgw=r70.research.bell-labs.com
274 auth=p9auth.research.bell-labs.com
275 ipnet=unix-room ip=135.104.117.0
277 ipnet=third-floor ip=135.104.51.0
281 Mappings between TCP service names and port numbers.
284 .ta \w'\fLtcp=sysmonxxxxx'u \w'\fLtcp=sysmonxxxxxport=512xxx'u
286 tcp=rexec port=512 restricted
292 first database file searched
298 .\" .IR ipconfig (8),
