Trying to get ping to work through iptables.

Rashkae ubuntu at
Tue Jan 6 15:39:42 UTC 2009

Martin McCormick wrote:
> 	I have set up the following iptables rules:
> sudo iptables -I INPUT 1 -i lo -j ACCEPT
> sudo iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
> sudo iptables -A INPUT -p tcp --dport echo -j ACCEPT
> sudo iptables -A INPUT -p tcp --dport ssh -j ACCEPT
> sudo iptables -A INPUT -j DROP
> 	Everything seems to work as expected except for ping
> (echo) which doesn't answer as long as the firewall is in
> effect.

You need to accept icmp protocol packets for things like ping and

/sbin/iptables -A INPUT -p icmp -j ACCEPT

Also, note that it's common practice to make your default Input Policy
Drop, rather than a rule in the chain.  Strictly speaking, I don't think
it makes a difference in the end, but it does make it possible to append
rules at the end of the chain later on.

/sbin/iptables -P INPUT DROP
/sbin/iptables -P FORWARD DROP

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