You won't believe guys, I fixed it!!! And the problem was nothing to do with networking! I was trying cachecc1, which is a cache for gcc, to compile a few programs. I liked it so I thought of putting it in /usr/local/lib. It is a .so (shared library) and has to be loaded using LD_PRELOAD. I had added following lines to /etc/profile so that every user would enjoy the benefits of cachecc1. CACHECC_HOME=/usr/local/bin/ CACHECC1_DIR=/work/cachecc1-base/cachecc-$USER/ LD_PRELOAD=$CACHECC_HOME/cachecc1.so That must have caused the problem because I removed these lines from /etc/profile, rebooted the system and everything worked like before. And yes, I had rebooted it 3-4 time before removing those lines from /etc/profile, and it did not work. Thanks for your efforts though. Regards from Vijay
