IP forwarding
The kernel setting that lets a Linux machine pass packets between its interfaces, acting as a router.
In more detail
It is off by default. sysctl -w net.ipv4.ip_forward=1 turns it on now, and a file in /etc/sysctl.d keeps it on after reboot.
Related terms
- DNAT and SNAT — Rewriting packet addresses: DNAT changes the destination, as in port forwarding, while SNAT and masquerade change the source so private hosts can share one public address.
Taught in
- One Rule, Four Firewalls: firewalld, ufw, nftables And iptables — CompTIA Linux+ (XK0-006) Exam Prep