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NDB(8)									NDB(8)

       query,  ipquery,	 mkhash, mkdb, mkhosts, cs, csquery, dns, dnstcp, dns‐
       query, dnsdebug, inform - network database

       ndb/query [ -am ] [ -f dbfile ] attr value [ rattr ]
       ndb/ipquery attr value rattr...
       ndb/mkhash file attr
       ndb/mkhosts [ domain [ dbfile ] ]
       ndb/cs [ -4n ] [ -f dbfile ] [ -x netmtpt ]
       ndb/csquery [ -s ] [ server [ addr...  ] ]
       ndb/dns [ -norRs ] [ -a maxage ] [ -f dbfile ]  [  -N  target  ]	 [  -x
       netmtpt ] [ -z program ]
       ndb/dnstcp [ -rR ] [ -f dbfile ] [ -x netmtpt ] [ conn-dir ]
       ndb/dnsdebug [ -rx ] [ -f dbfile ] [ [ @server ] domain-name [ type ] ]
       ndb/inform [ -x netmtpt ]

       The  network  database holds administrative information used by network
       programs such as dhcpd(8), ipconfig(8), con(1), etc.

       Ndb/query searches the database dbfile (/lib/ndb/local by default)  for
       an  attribute of type attr and value value.  If rattr is not specified,
       all entries matched by the search are printed.  If rattr is  specified,
       the  value  of  the  first pair with attribute rattr of all the matched
       entries normally is printed.  Under -m and rattr,  the  values  of  all
       pairs  with  a  rattr  attribute	 within	 the  first matching entry are
       printed.	 Under -a  and	rattr,	all  values  of	 pairs	with  a	 rattr
       attribute within all entries are printed.

       Ndb/ipquery uses ndbipinfo (see ndb(2)) to search for the values of the
       attributes rattr corresponding to the system with entries of  attribute
       type attr and value value.

       Ndb/inform  sends an RFC2136 DNS inform packet to a nameserver to asso‐
       ciate the host's IPv4 address with its DNS name.	 This is  required  if
       the  domain's  nameserver  is a Microsoft Windows Active Directory con‐
       troller.	 The host's domain name will be	 sent  to  the	AD  controller
       unless a tuple of the form inform=xxx is found in the host's ndb entry.

   Database maintenance
       Ndb/mkhash  creates  a hash file for all entries with attribute attr in
       database file file.  The hash files are used by ndb/query  and  by  the
       ndb library routines.

       Ndb/mkdb is used in concert with awk(1) scripts to convert uucp systems
       files and IP host files into database files.  It is  very  specific  to
       the situation at Murray Hill.

       When the database files change underfoot, ndb/cs and ndb/dns track them
       properly.  Nonetheless, to keep the database searches efficient	it  is
       necessary to run ndb/mkhash whenever the files are modified.  It may be
       profitable to control this by a frequent cron(8) job.

       Ndb/mkhosts generates a BSD style  hosts,  hosts.txt,  and  hosts.equiv
       files from an ndb data base file specified on the command line (default
       /lib/ndb/local).	 For local reasons the files  are  called  hosts.1127,
       astro.txt, and hosts.equiv.

   Connection service
       Ndb/cs  is  a server used by dial(2) to translate network names.	 It is
       started at boot time.  It finds out what	 networks  are	configured  by
       looking	for  /net/*/clone  when	 it starts.  It can also be told about
       networks by writing to /net/cs a message of the form:

	      add net1 net2 ...

       Ndb/cs also sets the system name in /dev/sysname if it  can  figure  it
       out.  The options are:

       -4     Only  look  up  IPv4  addresses (A records) when consulting DNS.
	      The default is to also look  up  v6  addresses  (AAAA  records).
	      Writing to /net/cs will toggle IP v6 look-ups.

       -f     supplies	the  name  of  the  data  base	file  to  use, default

       -n     causes cs to do nothing but set the system name.

       -x     specifies the mount point of the network.

       Ndb/csquery  queries  ndb/cs  to	 see  how   it	 resolves   addresses.
       Ndb/csquery  prompts  for  addresses  and  prints  what ndb/cs returns.
       Server defaults to /net/cs.  If any addrs  are  specified,  ndb/csquery
       prints  their translations and immediately exits.  The exit status will
       be nil only if all addresses were successfully translated.  The -s flag
       sets exit status without printing any results.

   Domain name service
       Ndb/dns serves ndb/cs and remote systems by translating Internet domain
       names.  Ndb/dns is started at boot time.	 By default  dns  serves  only
       requests	 written  to  /net/dns.	 Programs must seek to offset 0 before
       reading or writing /net/dns or /net/cs.	The options are:

       -a     sets the maximum time in seconds	that  an  unreferenced	domain
	      name will remain cached.	The default is one hour (3600).

       -f     supplies	the  name  of  the  data  base	file  to  use, default

       -n     whenever a DNS zone that we serve changes, send UDP NOTIFY  mes‐
	      sages to any dns slaves for that zone (see the attribute below).

       -N     sets  the	 goal  for the number of domain names cached to target
	      rather than the default of 8,000.

       -o     used with -s, -o causes dns to assume that it  straddles	inside
	      and  outside networks and that the outside network is mounted on
	      /net.alt.	  Queries  for	inside	addresses  will	 be  sent  via
	      /net/udp	(or  /net/tcp  in  response  to truncated replies) and
	      those for outside addresses via /net.alt/udp (or	/net.alt/tcp).
	      This  makes  dns	suitable  for serving non-Plan-9 systems in an
	      organization with firewalls, DNS proxies, etc., particularly  if
	      they  don't  work	 very well.  See `Straddling Server' below for

       -r     act as a resolver only: send  `recursive'	 queries,  asking  the
	      other  servers  to complete lookups.  If present, /env/DNSSERVER
	      must  be	a  space-separated  list  of  such  DNS	 servers'   IP
	      addresses,  otherwise  optional  ndb(6)  dns attributes name DNS
	      servers to forward queries to.

       -R     ignore the `recursive' bit on incoming requests.	 Do  not  com‐
	      plete lookups on behalf of remote systems.

       -s     also answer domain requests sent to UDP port 53.

       -x     specifies the mount point of the network.

       -z     whenever	we  receive a UDP NOTIFY message, run program with the
	      domain name of the area as its argument.

       When the -r option is specified, the servers used  come	from  the  dns
       attribute  in  the  database.   For  example,  to  specify a set of dns
       servers that will resolve requests for systems on the network mh-net:

	      ipnet=mh-net ip= ipmask=
	      dom=ns1.cs.bell-labs.com ip=
	      dom=ns2.cs.bell-labs.com ip=

       The server for a domain is indicated by	a  database  entry  containing
       both a dom and a ns attribute.

	      dom=A.ROOT-SERVERS.NET ip=
	      dom=B.ROOT-SERVERS.NET ip=
	      dom=C.ROOT-SERVERS.NET ip=

       The last three lines provide a mapping for the server names to their ip
       addresses.  This is only a hint and will be superseded from whatever is
       learned from servers owning the domain.

   Authoritative Name Servers
       You  can	 also  serve a subtree of the domain name space from the local
       database.  You indicate subtrees that you would like to serve by adding
       an  soa=	 attribute  to	the root entry.	 For example, the Bell Labs CS
       research domain is:

	      dom=cs.bell-labs.com soa=
		   refresh=3600 ttl=3600
		   mx=mail.research.bell-labs.com pref=20
		   mx=plan9.bell-labs.com pref=10

       Here, the mb entry is the mail address of the  person  responsible  for
       the  domain  (default postmaster).  The mx entries list mail exchangers
       for the domain name and refresh and ttl define the area refresh	inter‐
       val  and	 the  minimum  TTL  for	 records in this domain.  The dnsslave
       entries specify slave DNS servers that  should  be  notified  when  the
       domain changes.	The notification also requires the -n flag.

   Reverse Domains
       You  can	 also serve reverse lookups (returning the name that goes with
       an IP address) by adding an soa= attribute to the  entry	 defining  the
       root of the reverse space.

       For  example,  to  provide reverse lookup for all addresses in starting
       with or ndb must contain a record like:

	      dom=104.135.in-addr.arpa soa=
		   dom=d.f.ip6.arpa soa=    # special case, rfc 4193
		   refresh=3600 ttl=3600

       Notice the form of the reverse address.	For IPv4, it's	the  bytes  of
       the  address  range  you are serving reversed and expressed in decimal,
       and with appended.  For IPv6, it's the nibbles (4-bit  fields)  of  the
       address	range  you  are serving reversed and expressed in hexadecimal,
       and with appended.  These are the standard forms for a domain name in a
       PTR record.

       If  such	 an  soa  entry exists in the database, reverse addresses will
       automatically be generated from any IP addresses in the	database  that
       are under this root.  For example

	      dom=ns1.cs.bell-labs.com ip=

       will   automatically  create  both  forward  and	 reverse  entries  for
       ns1.cs.bell-labs.com.  Unlike other DNS servers, there's no way to gen‐
       erate inconsistent forward and reverse entries.

   Classless reverse delegation
       Following  RFC  2317, it is possible to serve reverse DNS data for IPv4
       subnets smaller than /24.  Declare  the	non-/24	 subnet,  the  reverse
       domain and the individual systems.

       For example, this is how to serve RFC-2317 ptr records for the subnet

	      ipnet=our-t1 ip= ipmask=/123
	      dom= soa=
		   refresh=3600 ttl=3600
	      ip= dom=router.our-domain.com

   Delegating Name Service Authority
       Delegation of a further subtree to another set of name servers is indi‐
       cated by an soa=delegated attribute.


       Nameservers within the delegated domain (as in this example) must  have
       their IP addresses listed elsewhere in ndb files.

   Wildcards, MX and CNAME records
       Wild-carded  domain  names can also be used.  For example, to specify a
       mail forwarder for all Bell Labs research systems:


       `Cname' aliases may be established by adding a cname  attribute	giving
       the  real  domain  name;	 the name attached to the dom attribute is the
       alias.  `Cname' aliases are severely restricted; the aliases  may  have
       no  other attributes than dom and are daily further restricted in their
       use by new RFCs.

	      cname=anna.cs.bell-labs.com dom=www.cs.bell-labs.com

       makes www....  a synonym for the canonical name anna.....

   Straddling Server
       Many companies have an inside network  protected	 from  outside	access
       with  firewalls.	  They usually provide internal `root' DNS servers (of
       varying reliability and correctness) that serve	internal  domains  and
       pass  on	 DNS  queries for outside domains to the outside, relaying the
       results back and caching them for future	 use.	Some  companies	 don't
       even  let  DNS  queries	nor replies through their firewalls at all, in
       either direction.

       In such a situation, running dns -so on a machine that  imports	access
       to  the	outside network via /net.alt from a machine that straddles the
       firewalls, or that straddles the firewalls itself,  will	 let  internal
       machines	 query	such  a machine and receive answers from outside name‐
       servers	for  outside  addresses	 and  inside  nameservers  for	inside
       addresses,  giving the appearance of a unified domain name space, while
       bypassing the corporate DNS proxies or firewalls.   This	 is  different
       from  running  dns -s and dns -sRx /net.alt -f /lib/ndb/external on the
       same machine, which keeps the inside and	 outside  namespaces  entirely

       Under -o, several sys names are significant: inside-dom, inside-ns, and
       outside-ns.  Inside-dom should contain a series	of  dom	 pairs	naming
       domains	internal  to  the  organization.   Inside-ns  should contain a
       series of ip pairs naming the internal DNS `root' servers.   Outside-ns
       should  contain a series of ip pairs naming the external DNS servers to

   Zone Transfers and TCP
       Dnstcp is invoked, usually from /rc/bin/service/tcp53,  to  answer  DNS
       queries	with  long  answers via TCP, notably to transfer a zone within
       the database dbfile (default /lib/ndb/local) to its invoker on the net‐
       work  at	 netmtpt  (default /net).  Standard input will be read for DNS
       requests and the DNS answers will appear on standard output.  Recursion
       is  disabled  by	 -R;  acting  as a pure resolver is enabled by -r.  If
       conn-dir	 is  provided,	it  is	assumed	 to  be	 a  directory	within
       netmtpt/tcp and is used to find the caller's address.

   DNS Queries and Debugging
       Ndb/dnsquery  can  be  used  to	query  ndb/dns	to see how it resolves
       requests.  Ndb/dnsquery prompts for commands of the form

	      domain-name request-type

       where request-type can be ip, ipv6, mx, ns, cname, ptr....  In the case
       of  the	inverse	 query type, ptr, dnsquery will reverse the ip address
       and tack on the .in-addr.arpa if necessary.

       Ndb/dnsdebug is like ndb/dnsquery but bypasses the  local  server.   It
       communicates  via  UDP (and sometimes TCP) with the domain name servers
       in the same way that the local resolver would and displays all  packets
       received.   The	query  can  be specified on the command line or can be
       prompted for.  The queries look like those  of  ndb/dnsquery  with  one
       addition.   Ndb/dnsdebug	 can  be  directed  to query a particular name
       server by the command @name-server.  From that point on, all queries go
       to that name server rather than being resolved by dnsdebug.  The @ com‐
       mand returns query resolution to dnsdebug.  Finally, any	 command  pre‐
       ceded by a @name-server sets the name server only for that command.

       Normally	 dnsdebug  uses	 the  /net  interface  and  the	 database file
       /lib/ndb/local.	The -f option supplies the name of the data base  file
       to  use.	  The  -r  option  is  the same as for ndb/dns.	 The -x option
       directs dnsdebug to use the /net.alt  interface	and  /lib/ndb/external
       database file.

       Look up helix in ndb.

	      % ndb/query sys helix
	      sys=helix dom=helix.research.bell-labs.com bootf=/mips/9powerboot
		   ip= ether=080069020427

       Look up plan9.bell-labs.com and its IP address in the DNS.

	      % ndb/dnsquery
	      > plan9.bell-labs.com ip
	      plan9.bell-labs.com ip
	      > ptr ptr	 plan9.bell-labs.com ptr	 ampl.com

       Print the names of all PCs that boot via PXE.

	      % ndb/query -a bootf /386/9boot sys

	      resolver's DNS servers' IP addresses.

	      first database file searched

	      hash files for /lib/ndb/local

	      service file for ndb/cs

	      where /srv/cs gets mounted

	      service file for ndb/dns

	      where /srv/dns gets mounted


       ndb(2), ndb(6)

       Ndb  databases are case-sensitive; ethernet addresses must be in lower-
       case hexadecimal.

                             _         _         _ 
                            | |       | |       | |     
                            | |       | |       | |     
                         __ | | __ __ | | __ __ | | __  
                         \ \| |/ / \ \| |/ / \ \| |/ /  
                          \ \ / /   \ \ / /   \ \ / /   
                           \   /     \   /     \   /    
                            \_/       \_/       \_/ 
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