Well I spent a few hours yesterday trying to figure out why DNS was failing in some cases.
We use OpenDNS server then fallback to googles.
Yesterday nslookup test.uribl.com.multi.uribl.com failed.
After a while I found the following …
OpenDNS server returns server unknown :
nslookup test.uribl.com.multi.uribl.com 126.96.36.199
** server can't find test.uribl.com.multi.uribl.com: NXDOMAIN
While google works correctly :
nslookup test.uribl.com.multi.uribl.com 188.8.131.52
I have now switched to use google DNS only. I have no idea why OpenDNS fails for this lookup but not any other.