I don't understand this iptables rule -i lo

Melsync · 09-19-2006, 06:46 AM

I entered this command into my Fedora firewall:

/sbin/iptables -A RH-Firewall-1-INPUT -i lo -j ACCEPT

When I read the table,
/sbin/iptables -L

I think that, according to the rules sorting order, the rule above corresponds to this line:
target prot opt source destination
ACCEPT all -- anywhere anywhere

I read that the rule stands for allowing anything over loopback. What does it mean and why does the iptable entry look so scary?

Thank you.

win32sux · 09-19-2006, 07:06 AM

Quote:

Originally Posted by Melsync

I entered this command into my Fedora firewall:

/sbin/iptables -A RH-Firewall-1-INPUT -i lo -j ACCEPT

When I read the table,
/sbin/iptables -L

I think that, according to the rules sorting order, the rule above corresponds to this line:
target prot opt source destination
ACCEPT all -- anywhere anywhere

I read that the rule stands for allowing anything over loopback. What does it mean and why does the iptable entry look so scary?

Thank you.

yeah, the rule means "if packet comes-in through the loopback interface, send it to ACCEPT"... the reason it looks scary in your output is cuz it's not verbose enough... it's less scarier like this:

Code:

iptables -L -v -n

Melsync · 09-19-2006, 07:13 AM

I understand. The verbose output precises that 'in' is 'lo', not 'all' or anything like that.
Thanks a lot.