5

I need to forward an interface and I wonder why it is disabled by default.

Will there be security issues or side effects when I enable it?

Improve this question

1 Answer 1

Reset to default
5

ip_forward is only useful on multihomed systems (i.e. more than one network interface) and makes routing of network packets between those interfaces possible. By enabling ip_forward your box essentially becomes a router.

Routing is an optional network function and as such disabled by default.

As for the downside/possible risks: when one of those interfaces is facing a public subnet (WAN/internet or possible hostile LAN), routing makes attacks possible. That's why you need to address those potential security issues with a firewall.

There is an excellent answer at What is kernel ip forwarding? with more information on the subject.

Improve this answer

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .