Local DNS Caching not caching on external interface

[Chad Gross]

On 12/15/06, Tek Bahadur Limbu <teklimbu at wlink.com.np> wrote:
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> On Thu, 14 Dec 2006 08:34:11 -0500
> "Chad Gross" <avatar4d at gmail.com> wrote:
>
> > On 12/14/06, Tek Bahadur Limbu <teklimbu at wlink.com.np> wrote:
> > >
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> > > On Thu, 14 Dec 2006 01:08:11 -0800
> > > Christopher Cowart <ccowart at rescomp.berkeley.edu> wrote:
> > >
> > > > On 14:57 Thu 14 Dec     , Tek Bahadur Limbu wrote:
> > > > > Dear All,
> > > > >
> > > > > I am very new to Bind and FreeBSD.
> > > > >
> > > > > I have just configured a Local DNS server using the built-in
> > > > > Bind 9.3.1 on a FreeBSD 5.4 machine.
> > > > >
> > > > > My problem is that the machine can cache queries on the
> > > > > localhost and loop back (127.0.0.1) interface only.
> > > > >
> > > > > I have a public static IP on this machine too and I can't seem
> > > > > to query the caching name server from my local network.
> > > > >
> > > > > In Linux, this is no problem. I just can't seem to get Bind to
> > > > > work as in my local network. It works only on the loopback
> > > > > interface.
> > > >
> > > > The default /etc/namedb/named.conf configuration file for BIND
> > > > says:
> > > >
> > > > | // If named is being used only as a local resolver, this is a
> > > > | safe default. // For named to be accessible to the network,
> > > > | comment this option, specify // the proper IP address, or
> > > > | delete this option. listen-on   { 127.0.0.1; };
> > > >
> > > > It looks like if you comment out that option, it will listen on *
> > > > by default. You could also add the other IP address on which you
> > > > want named to listen.
> > > >
> > > > --
> > > > Chris Cowart
> > > > Network and Infrastructure Systems Administrator
> > > > RSSP-IT, UC Berkeley
> > > > "May all your pushes be popped"
> > > >
> > >
> > > Dear Chris,
> > >
> > > Thank you for your help. I did comment and added my public static IP
> > > like the following:
> > >
> > >
> > > listen-on       { 202.x.x.x; }; # My Static IP
> > >
> > > Now when I do from my local PC:
> > >
> > > dig yahoo.com @202.x.x.x , I can do DNS lookups.
> > >
> > > But when I try doing that from another computer on my network, I
> > > can't do any DNS lookups.
> > >
> > >
> > > Is that anything that I miss?
> > >
> > >
> > > - --
> > >
> > >
> > > With best regards and good wishes,
> > >
> > > Yours sincerely,
> > >
> > > Tek Bahadur Limbu
> > >
> > > (TAG/TDG Group)
> > > Jwl Systems Department
> > >
> > > Worldlink Communications Pvt. Ltd.
> > >
> > > Jawalakhel, Nepal
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> > > _______________________________________________
> >
> >
> >
> > You have to tell the other machines on your network to use the IP of
> > the local DNS server for domain name resolution. If you are using
> > DHCP you can configure your DHCP server to give this information with
> > the IP. Otherwise you must manually do it, which will be different
> > between operating systems.
> >
> > HINT: In FreeBSD add the IP of the DNS server to /etc/resolve.conf
> >
> > Chad
> >
>
>
> Dear Chad,
>
> I just get the following logs while troubleshooting with tcpdump.
>
> local nameserver IP: 202.102.5.100
> network PC IP: 202.102.5.50
>
> When I do a nslookup of yahoo and google from network PC using the
> local caching nameserver, I only get this on the caching nameserver.
>
> 13:23:58.707604 IP 202.102.5.50.44778 > 202.102.5.100.53:  56955+ A?
> google.com. (28)
> 13:23:32.899379 IP 202.102.5.50.40229 > 202.102.5.100.53:  47636+ A?
> yahoo.com. (27)
>
>
> Note: Please note that the above Static IPs are just arbitrary values.
>
> Can you please shed some light on this issue?
>
> - --
>
>
> With best regards and good wishes,
>
> Yours sincerely,
>
> Tek Bahadur Limbu
>
> (TAG/TDG Group)
> Jwl Systems Department
>
> Worldlink Communications Pvt. Ltd.
>
> Jawalakhel, Nepal
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Tek,

Can you please post your Bind configuration files?

Have you done a tcpdump or wireshark capture on both machines while issuing
the resolution request? Could you please do that as well and post the
results?

Chad