After doing an ufw enable on Ubuntu 14.04 host and rebooting, my CentOS VM IP wont establish (come up) even when manually doing a manual ifup when bringing it up. I get connection timed out when doing ifup ifcfg-eth0. If I do a ufw disable everything will work fine. It appears the host firewall is blocking something, but what? I don't know what to allow in for this?