I've a squid server setup. I need to allow squid users to login from specific IPs only. ie one user should be able to login from only that IP specified for that user. Is it possible?

Yes. Set up your ACL however you wish. There is much documentation on setting up ACL's...what have you done/tried/researched so far???
http://wiki.squid-cache.org/SquidFaq/SquidAcl
http://www.deckle.co.uk/squid-users-...operators.html

Ok, I was able to do this in a different way using the following rules in squid.conf.

======================
acl group1 proxy_auth "/usr/local/squid_1/etc/group1"
acl group1_ip src 1.2.3.4
http_access allow group1 group1_ip
======================

I tried to specify the users directly in the acl but its not working, so I had to add the users in a file and the location to the file was specified.

Using acl i added users to a group (group1) and the IPs to a different group (group1_ip), then created a rule to allow users in group1 to login only from group1_ip.

Is there a more simpler way?