DNS(8)                                                     DNS(8)

     NAME
          dns, dnsquery - domain name service

     SYNOPSIS
          ndb/dns [ -f dnsfile ] [ -h ] [ -r ] [ -x net ]

          ndb/dnsquery [ -x net ] [ address ... ]

     DESCRIPTION
          Dns is an Internet Domain Name Service (DNS) resolver.  By
          default it serves a file /net/dns, that clients such as
          cs(8) write and read to retrieve network data associated
          with domain names and Internet addresses.  The -f option
          specifies the network database that contains the local DNS
          data (default: /lib/ndb/local).  The -x option specifies an
          alternative mount point for the network (default: /net).
          When Inferno is running hosted, dns normally uses the host's
          own DNS resolver first (via srv(2)), before searching the
          DNS itself; that way domain names can be used in Inferno
          with minimal configuration.  The -h option stops dns from
          using the host data.  In the absence of local data, by
          default dns consults the external DNS directly using some
          bootstrap data, but if -r is specified and local resolvers
          are given in the configuration file, dns(6), dns will query
          them first for all addresses, before resorting to external
          DNS servers.

          Dnsquery queries the given server (default: /net/cs) for a
          translation of each address and prints the results, one per
          line.  If no address is given, dnsquery prompts for some-
          thing to find in the DNS, one per line on the standard
          input, of the form:

               name [attribute]

          where name is the label of something in the DNS, and
          attribute is one of its attributes from the list below:

          all     all data currently known locally for name
          cname   name for which name is an alias
          hinfo   host and operating system type
          ip      for an IP address when name is a domain name
          mx      mail exchanger
          ns      for a list of name servers
          ptr     for the domain name when name is an Internet address
          soa     statement-of-authority

          Dnsquery queries the server for that name/attribute combina-
          tion and prints the results, one per line.  If an attribute
          is not given, dnsquery uses ip if name looks like a domain

     DNS(8)                                                     DNS(8)

          name, and ptr if it looks like an Internet address.

     FILES
          #sdns*          service directory
          /net/dns        domain name service
          /lib/ndb/local  network database
          /lib/ndb/dns    DNS bootstrap data

     SOURCE
          /appl/cmd/ndb/dns.b
          /appl/cmd/ndb/dnsquery.b

     SEE ALSO
          dns(6), cs(8)

     BUGS
          Dns does not yet offer an external DNS server, mainly for
          lack of a suitable database for local zone data.