I installed 12.04 from the July 19th image 29194.
after install completed (hybrid core), the MD came up fine. In Firefox, I can navigate pages. Apt update/install works as well. When 'pinging' from core (ping ubuntu.org), the name gets resolved to an IP, but ping times out. Cannot ping localhost or dcerouter either. Pinging IPs fails too.
Additionally, a workstation getting an IP from the core (Non-MD) cannot ping anything.
I installed ufw... and ran the command 'ufw enable' followed by 'ufw reset'. Ping started working. However on reboot of the core, everything reverts back to LMCE default Firewall settings.
Is there a workaround? I didnt see any posts in the forums by others with same issue.