I'm running centos 5.8 on a local machine at home. Today I was trying to analyze the DNS-Lookup via dig.

$ dig +trace -t A www.heise.de.

This is giving me something like this as a response

de.         172800  IN  NS  f.nic.de.
de.         172800  IN  NS  z.nic.de.
de.         172800  IN  NS  s.de.net.
de.         172800  IN  NS  n.de.net.
de.         172800  IN  NS  a.nic.de.
de.         172800  IN  NS  l.de.net.
;; Received 344 bytes from 192.58.128.30#53(192.58.128.30) in 49 ms

In contrast my dedicated CentOS machine is returning the following

 de.            172800  IN  NS  a.nic.de.
 de.            172800  IN  NS  n.de.net.
 de.            172800  IN  NS  f.nic.de.
 de.            172800  IN  NS  z.nic.de.
 de.            172800  IN  NS  l.de.net.
 de.            172800  IN  NS  s.de.net.
 ;; Received 344 bytes from 192.58.128.30#53(j.root-servers.net) in 32 ms

As you can see, the last line is different. Any idea why my dedicated machine is giving me the host name of the responding DNS-Server and my local machine is only returning the ip-address?

Thanks in advance

UPDATE

The reverse DNS-Lookup is working without any problems. Also, I just checked this on my local mac and...exactly the same problem occurs. Is it possible that this has to do with the local router/modem/ISP?