IP Networking

hello,,

after googling a lot,, i still cannot find the answer to my problem.

i want to do a traceroute or a network debugging of dns lookups from a Mail Server running on DEBIAN LENNY 5.0.

we have 2 routers in our office,, and i want to see through which of the routers the dns lookups are done

can someone advise me how to ..... ??? Thanks,,,

You might try the dig utility. Should work for what you described.

Code:

       +[no]trace
	   Toggle tracing of the delegation path from the root name servers
	   for the name being looked up. Tracing is disabled by default. When
	   tracing is enabled, dig makes iterative queries to resolve the name
	   being looked up. It will follow referrals from the root servers,
	   showing the answer from each server that was used to resolve the
	   lookup.

nslookup with debug on will tell you where it goes. Usually the local dns talks to the ISP dns as a local root, and usually is on the internet and can do without recursion, perhaps must under the isp contract. This way, the isp tells you the root servers and you go off on your own to their children. If the roots change, the changes trickle down.

traceroute from the dns host of the DNS server IPs will tell you where the network path is, going out. It may vary depending on where the next DNS server is.

(nslookup with server name allows you to route dns direct to a specific name server, if you want to compare responses.)

ok,,, thanks