2024-bsc-sebastian-lenzlinger/notes/wiki/ip-forwarding.md

Resources: archwiki-internet-sharing archwiki-sysctl kernel-sysctl

Remark: Many resources mention that all #firewall config should be executed in one go from a script. They also mention to make sure to flush all previous rules/tables/chains before beginning the setup. Order of rules matter.

Check current settings

sudo sysctl -a | grep forward

Config

net.ipv4.conf.all.bc_forwarding = 0 # broadcast?
net.ipv4.conf.all.forwarding = 1 # Enable IP forwarding on this interface.

Latter above controls whether packets received on this (in this case on all) interface can be forwarded.

net.ipv4.conf.all.mc_forwarding = 0 # Multicast routing

Locations

Preloaded

Tags

#firewall #nat #sysctl #ip-forwarding #masquerading