IPTables allow ping.

[Bharath Ramesh <bramesh@vt.edu>]

I have a debian amd64 box. I am writing a set of firewall rules. I want
to be able to ping my machine from outside. I wrote the following rule.
I am still unable to ping my machine from outside. Could someone verify
that my rule is correct.

# Allow to/be ping(ed).
$IPT --append INPUT --in-interface $EXTIF --protocol icmp --icmp-type 0 \
      --destination $EXTIP --match state --state NEW,ESTABLISHED,RELATED \
      --jump ACCEPT
$IPT --append INPUT --in-interface $EXTIF --protocol icmp --icmp-type 8 \
	--destination $EXTIP --match state --state NEW,ESTABLISHED,RELATED \
	--jump ACCEPT
$IPT --append OUTPUT --out-interface $EXTIF --protocol icmp --icmp-type 0 \
	--source $EXTIP --match state --state NEW,ESTABLISHED,RELATED \
	--jump ACCEPT
$IPT --append OUTPUT --out-interface $EXTIF --protocol icmp --icmp-type 8 \
	--source $EXTIP --match state --state NEW,ESTABLISHED,RELATED \
	--jump ACCEPT

I am able to ping other m/c from my m/c but I am not able to ping from
outside.

Thanks,

Bharath

---
Bharath Ramesh       <bramesh@vt.edu>       http://people.cs.vt.edu/~bramesh