Ljubomir Ljubojevic wrote:
(1) I can open port 22 on the Billion, allowing me to ssh in from outside. But for some reason I cannot ping the same address from outside.
This is due to modem refuses to answer to pings. You might have option to allow it in modem config.
Ping (ICMP) does not use ports but it is packet of type 8.
Thanks again for your response. Could CentOS be preventing me from pinging the system?
When you turn off firewall, it stops routing packets so they can not be passed to systems behind it.
Only option I can think of is to use shorewall as firewall and add NAT/Masquerade and the rest of the rules to routestoped confgi file:
I was using Shorewall before I went over to CentOS-6, and will probably go over to it.
But I don't really need to disable the firewall on the server. I just thought I'd try it as an experiment.