Yum stopped working after F14 -> F15 upgrade

[Manish Kathuria]

Hello,

I have upgraded from F14 to F15 using preupgrade and everything seems
to be okay except yum. Whenever I run yum, it terminates giving the
error:

Error: Cannot retrieve metalink for repository: updates. Please verify
its path and try again

The error message appeared for other repositories also. In order to
sort out the problem I have tried out the following:

1. Disabled livna, rpmfusion and other repositories.
2. Disabled ipv6
3. Created entries in /etc/hosts for mirror.fedoraproject.org
4. Reinstalled yum, fedora-release-15-1

However, none of this has solved the problem. DNS is working fine and
all other internet applications are able to resolve sites. Any
suggestions?

Thanks,
-- 
Manish Kathuria