Performed Component updates - Network/Firewall modules on April 10,2017 which was successful. After that tried performing rest of updates which were failing.
Checked log /var/log/zentyal/zentyal.log file to find errors -
2017/04/10 22:20:09 ERROR> install-packages:94 main:: - Failed to fetch
http://security.ubuntu.com/ubuntu/pool/main/g/glibc/multiarch-support_2.23-0ubuntu7_amd64.deb Cannot initiate the connection to us.archive.ubuntu.com:80 (91.189.91.26). - connect (101: Network is unreachable) [IP: 91.189.91.26 80]
Traceroute also gave same error:
#traceroute yahoo.com
traceroute to yahoo.com (98.138.253.109), 30 hops max, 60 byte packets
connect: Network is unreachable
Issue: After component upgrade, routing to external network broke.
I have performed same upgrade on another system which did not have issue.!