Most likely when you login your system is not able to reverse-lookup your IP address... When you login type:

who am i

You will likely see an ip address in the last field...


Try to nslookup on this last field:

nslookup ip.ip.ip.ip

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While you are at it, answer the following questions:

Do you have a DNS server?
How is your nsswitch.conf file setup? (It's in /etc/nsswitch.conf if you are curious.).. Can you cut-and-paste this file into your reply?..

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Once you have done what I have suggested and provided the information I have request I can give you a solution to your problem..

- dEvNuL