Re: Iptables problem

["Saurabh Mehrotra" <saurabh1980@gmail.com>]

Thanks for reply .

Can you guide me how to set up TCP dump on RHEL 4 and test .

Can u explain this more so that I will calculate that..

"  packet counts for each rule, which
should help you to determine which rule is dropping or failing to
forward the DNS packets."

It will be helpful for me .

Thanks saurabh

On 1/26/07, Ted Phelps <phelps@gnusto.com> wrote:
> Hi Saurabh,
>
> "Saurabh Mehrotra" writes:
> > Please find output of
> >
> > iptables -v -L
>
> I'm afraid I'm not clever enough to comprehend what your rules are
> trying to do.  Also, I don't know what the IP address of trench1 is nor
> where the firewall is located in the network, so it's difficult to see
> which rules would be involved.
>
> The likely cause of your problem is that the DNS request or its reply is
> being dropped by your firewall.  The easiest way to see which is
> happening is to have tcpdump listen to port 53 on 212.165.108.4 to see
> if the request is coming in and if a reply is going out.
>
> The iptables output you sent has packet counts for each rule, which
> should help you to determine which rule is dropping or failing to
> forward the DNS packets.
>
> Hope that helps,
> -Ted