[afnog] Resolver issues

[Brian Candler]

On Mon, Apr 10, 2006 at 06:10:12PM +0300, Michuki Mwangi wrote:
> If i run tcpdump between to boxes i the checksum on one end is fine but 
> on reaching www its not ok. I want to try a couple of things including 
> changing the patch cord to see if that could be it before working on the 
> NIC.

As Geert Jan points out, this might be just an artefact of a NIC which does
checksum-offloading. Or it could be a driver error.

If TCP packets are working correctly, with no checksum errors shown, that's
strange though.

So it might also be useful to try other UDP queries, e.g. 

# ntpdate x.x.x.x

where x.x.x.x is an NTP server you have access to (uses UDP port 123).

For comparison purposes, you could also try DNS over TCP:

# dig +tcp @80.240.192.7 kenic.or.ke. ns

Regards,

Brian.