[c-nsp] DNS and NAT

[Roy]

I have done some more testing and it appears that any DNS response that 
contains an IP address is lost.  The problem must be related to a 
defective fixup in the NAT routine.  I haven't been able to figure out 
how to disable the DNS fixup in IOS

Roy

Roy wrote:
> I am trying to setup a Linux box behind a Cisco router that has NAT 
> turned on.
> I configured:
>
> ip nat inside source static udp 10.10.100.20 53 xx.xx.xx.xx 53 extendable
> ip nat inside source static tcp 10.10.100.20 53 xx.xx.xx.xx 53 extendable
>
> If I do
>
> dig . @xx.xx.xx.xx
>
> From the internet, I get the proper response.  tcpdump on linux shows 
> the packet arriving and a response packet.
>
> If I do
>
> dig domain.com @xx.xx.xx.xx
>
> I get no response.  tcpdump on the linux box shows a reply packet 
> leaving it and the router responding with ICMP host unreachable.
>
> Software is
>
> IOS (tm) C1700 Software (C1700-K9O3SY7-M), Version 12.3(18), RELEASE 
> SOFTWARE (fc3)
>
> Any ideas are welcome.
>
> Roy
>
>
>
>