After upgrade to Prime Infrastructure 3.9 from 3.7, DNS lookup didn't work from PI, and therefore repository URL didn't work because we are using DNS names for host-lookup.
After disabling Secure DNS as per bug fix, DNS lookup from Prime Infrastructure started working again.
bug fix:
conf t
no ip dnssec
exit
URL: https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvx06532
