Can anyone explain this for me? I'm not sure why it is behaving like this.

Using the Sidewinder DNS, we get truncation now. 192.168.5.1 is our MS Active Directory DNS server. 192.168.1.1 is our Sidewinder - zones are replicated from AD to Sidewinder.

[root@RHELhost ~]# nslookup
> server 192.168.1.1
Default server: 192.168.1.1
Address: 192.168.1.1#53
> 192.168.5.63
;; Truncated, retrying in TCP mode.
Server: 192.168.1.1
Address: 192.168.1.1#53

63.5.168.192.in-addr.arpa name = mad02h45490.ad.dot.state.wi.us.
> server 192.168.5.1
Default server: 192.168.5.1
Address: 192.168.5.1#53
> 192.168.5.63
Server: 192.168.5.1
Address: 192.168.5.1#53

63.5.168.192.in-addr.arpa name = mad02h45490.ad.dot.state.wi.us.
>

Figured it out. The sidewinder was sending back both the AUTHORITY SECTION and the ADDITIONAL SECTION on its reverse lookup requests which caused it to go beyond the 512 limit. Found this using dig instead of nslookup.

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