no, nslookup is just a way of getting the name out of an IP address. For example: 

[robricc@spmicro robricc]$ nslookup 68.41.48.90

Note:  nslookup is deprecated and may be removed from future releases.

Consider using the `dig' or `host' programs instead.  Run nslookup with

the `-sil[ent]' option to prevent this message from appearing.

Server:         209.94.100.100

Address:        209.94.100.100#53



Non-authoritative answer:

90.48.41.68.in-addr.arpa        name = bgp945768bgs.canton01.mi.comcast.net.



Authoritative answers can be found from:

41.68.in-addr.arpa      nameserver = NS01.JDC01.PA.comcast.net.

41.68.in-addr.arpa      nameserver = NS02.JDC01.PA.comcast.net.

NS01.JDC01.PA.comcast.net       internet address = 66.45.25.71

NS02.JDC01.PA.comcast.net       internet address = 66.45.25.72
_________________________
-Rob Riccardelli
80GB 16MB MK2 090000736