I have a dedicated server running Ubuntu 9.04. I have sites running fine on the server and are accessible from anywhere. However, pinging the server's IP address always results in timeouts.
I did some Googling and saw information that said to basically put 0 in the file /proc/sys/net/ipv4/icmp_echo_ignore_all. I checked and that was already the case (I ran the command on here just to make sure).
But the server is still not pingable. Is there something else that could be the problem?
PS. I have seen some places mention firewalls. I don't know if the server has a firewall installed (I haven't installed anything myself but the server came pre-built with everything). How would I find out if there is a firewall running? And can the server be pingable but keep the firewall running?
Most likely you would be running iptables as a firewall. Type iptables -L as root to see if there is a rule (or the lack thereof) for ICMP requests. If there are rules, save all using iptables-save, add an additional one for your ICMPs (for example -A INPUT -p icmp -j ACCEPT) and reload the entire batch with iptables-restore.