Useful service to see if you're behind a transparent DNS proxy

[docstrange]

This useful tidbit came across from Pawel Rogocz on the djbdns mailing list today.

If you don't know what actual host is really doing your DNS lookups - or you suspect that, despite having your DNS resolver set to xxx.xxx.xxx.xxx, some network trick is going on, and some other host is actually doing the lookups... you can look up whoami.ultradns.

Comments

[cheesetruck]

[truck@cube ~]$ nslookup
> server 4.2.2.1
Default server: 4.2.2.1
Address: 4.2.2.1#53
> whoami.ultradns.net
Server: 4.2.2.1
Address: 4.2.2.1#53

Non-authoritative answer:
Name: whoami.ultradns.net
Address: 209.244.7.33
>

Maybe I didn't understand, but should this not return 4.2.2.1 ?

[docstrange]

"You can even uncover nameserver's alternate IPs this way."

And see, you did.

[cheesetruck]

Ok. What I did not paste before was several other servers returning the same result.

However, as of right now, they are all returning the addresses I expect.

This may be simply having looked at too many numbers today. I looked at, um, one. I think. Earlier. (:

[docstrange]

Math is hard!