dev# nslookup 209.85.135.99
Server:         10.0.0.1
Address:        10.0.0.1#53

Non-authoritative answer:
99.135.85.209.in-addr.arpa      name = mu-in-f99.google.com.

Authoritative answers can be found from:
135.85.209.in-addr.arpa nameserver = ns1.google.com.
135.85.209.in-addr.arpa nameserver = ns2.google.com.
135.85.209.in-addr.arpa nameserver = ns3.google.com.
135.85.209.in-addr.arpa nameserver = ns4.google.com.
ns4.google.com  internet address = 216.239.38.10
ns2.google.com  internet address = 216.239.34.10
ns3.google.com  internet address = 216.239.36.10
ns1.google.com  internet address = 216.239.32.10