After much R&D finally figured out that the problem was with the DNS resolver - which got overwritten during the upgrade somehow. The quick hack is to just edit the file and enter the DNS name servers. Here's the output :
vibhu@zion:~$ cat /etc/resolv.confPut the IP addresses of your name servers instead of the xx's
# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
# DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
nameserver xx.xx.xx.xx
nameserver xx.xx.xx.xx
The puzzle which still exists is why the DNS is not put in automatically. Still looking at that