DNS(1)                  XR32 REFERENCE MANUAL                23/1/2013

COMMAND
        DNS -- Domain Name Server commands.

SYNOPSIS
        DNS {<add | drop> <ipaddr>} | <list>

AVAILABILITY
        Sysop-only.

DESCRIPTION
        The DNS commands are used to add and delete Domain Name
        Servers from the DNS list, and to display the list.

        Domain Name Servers are external TCP/IP hosts which are used
        to resolve host names, for example "bbc.co.uk", into IP
        addresses, when the information is not found locally in
        DOMAIN.SYS.

        In order for XR32 to use this process, it needs to know the IP
        addresses of suitable DNS's.  These are usually specified in
        XROUTER.CFG.

        If no servers are specified, XR32 will use the domain
        resolution services provided by Windows.

        The "Split DNS" system used by XR32 allows private domains to
        be resolved using their own servers.

OPTIONS
        a) "DNS ADD <ipaddr> [domain]" adds the name server whose IP
           address is specified by <ipaddr> to the server list.

           The [domain] argument may be specified with or without a
           trailing dot.  e.g. ".ampr.org" or ".ampr.org.".

           If [domain] is specified, the name server will only be used
           to resolve hostnames in that domain, and the hostnames in
           that domain will only be resolved using that server and no
           others.

           For example: "DNS=44.131.91.245 .ampr.org." tells XR32 to
           exclusively use the server 44.131.91.245 to resolve all
           ampr.org hostnames.  That server will not be used to
           resolve hosts outside the ampr.org domain, and ampr.org
           will not be resolved using any other server.


        b) "DNS DROP <ipaddr>" deletes the nameserver specified by
           <ipaddr> from the server list.

        c) "DNS LIST" displays the list of domain name servers.

EXAMPLES
        DNS ADD 44.131.91.245 .ampr.org.
        DNS ADD 62.31.117.22
        DNS DROP 44.131.88.73

FILES
        Domain servers are usually specified in XROUTER.CFG using
        one or more "DNS=<ipaddr> [domain]" directives. Alternatively,
        the DNS ADD command may be used in BOOTCMDS.SYS. Omit the
        directives to force the use of Windows DNS.

HISTORY
        This command, and the DNS server / client were necessary in
        DOS XRouter, but have less relevance in XR32 because Windows
        provides Domain Resolution services.

        However, the facilities were not deleted when the code was
        ported to XR32, because it is conceivable that (a) someone
        might wish to use an external DNS via SLIP or PPP or RF
        because Windows has no Internet connection (Imagine a node
        on a remote site, with no internet connection), or (b) they
        may wish to act as a DNS for TCP/IP over radio.

NOTE
        If Xrouter obtains its IP address via DHCP or PPP, it will
        automatically obtain primary and secondary DNS addresses, and
        remove them from the list when the lease terminates.

DNS(1)                         END OF DOCUMENT