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 From:  Joey Morin <joeymorin at gmail dot com>
 To:  m0n0wall <m0n0wall at lists dot m0n0 dot ch>
 Subject:  dns forwarder
 Date:  Fri, 18 Dec 2009 20:59:42 -0500
i'm almost certain this is not a problem with m0n0wall, nor with my config,
but this list seems the best place to start.

i've got a server behind a m0n0.  i need to be able to reach it by the same
name internally as externally.  the dirty solution i've used in the past is
to create a dns forwarder entry for the external domain with an empty host
field, and to create inbound nat entries for each service that i need access
to (http, ftp, etc...).  this is an acceptable solution, since i have only
one server behind the m0n0.  if i had servcies running on more than one
machine, i couldn't use this trick.

this worked fine with my old slackware server.  i could point to
http://my.domain from an internal machine, and dns served up the internal ip
of my server.  from an external machine, the same url would get me to the
same internal server via nat.

now that i've switched to ubuntu server, it doesn't work anymore.

i've confirmed that dns forwarding works.  from an internal machine i can
ping the machine by hostname:
$ ping hostname
PING hostname.my.domain ( 56(84) bytes of data.
64 bytes from hostname.my.domain ( icmp_seq=1 ttl=64 time=1.53

however, when i try by domain:
$ ping my.domain
PING my.domain ( 56(84) bytes of data.
--- my.domain ping statistics ---
45 packets transmitted, 0 received, 100% packet loss, time 44320ms

note that when pinging by domain, the resolved ip is correct, but no packets
are returned.

so it looks like ubuntu doesn't like the mis-match. slackware didn't have
the problem.  the problem is the same whether i try an unbuntu client or a
windows xp client.

any ideas what the problem is, or how to fix it?