From: Marcus Watts (mdwumich.edu)
Date: Wed Dec 01 2004 - 06:47:12 CST

• Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

Dave Smith <dms121yahoo.com> writes:
...
> Thanks for the reposnes guys. Can you help this novice
> by explaining how I go about checking the DNS
> resolver? My resolve.conf has both my nameservers
> which appear to respond, I also have: "lookup file
> bind" in there. I've had a look at my routing tables
> but really I'm not sure what I'm looking for. There is
> a route in there to the 192.168.2.225 machine...
...

The short answer is to learn to use the tools:

ktrace - try this on both whatever you use to connect to sendmail,
        and on sendmail itself. This will tell you every kernel
        call it makes. DNS queries will show up as a series
        of socket calls.
tcpdump - try this on the obsd end, perhaps experiment with filters,
        capture size, decoding or raw. This will show you the actual
        network traffic, including the formatted or unformatted data.
Other tools that could be useful include dig and gdb.

Other resources:
        IETF RFCs. This is the "official" documentation for
        what goes over the wire. The older stuff is even
        reasonably concise.

        obsd source. Everything you see happening is controlled
        by what's here. Learning to read this is perhaps one of
        the most valuable reasons for installing and running obsd.

                                -Marcus Watts

• Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]