question about default iptables config in ubuntu
I was wondering about the security of the default iptables configuration in ubuntu. I know that it does not filter ICMP packets by default. Is that a big deal? grc.com's ShieldsUp doesn't seem to like it if pings are replied to, and gives a "failed" rating to any machine that replies to them.
So, in your opinion, how secure is ubuntu's default iptables configuration?
Also, if a system is directly connected to a dsl or cable modem, and is running ubuntu with the default iptable configuration, what are the odds that the computer would be compromised or infected, after about five hours?