On Thu, 06 Feb 2020 12:19:26 +0000, Chinmay Agarwal said:
To check the same there is a condition in kernel code wherein we check if ipv6.devconf_all is set. Now, my query is that we are checking if forwarding is enabled on all interfaces, then we consider the system to be a router.
But even if forwarding is enabled from few interfaces(not all) isn't the system behaving like a router?
You can't actually configure "routing on some but not all" without setting the global forwarding bit. If you have the very odd use case where you have eth0, eth1, and eth2, and you're routing between eth0 and eth1, but eth2 is a private net that should *not* communicate with either eth0 or eth1, the way you configure that is to turn on the global forwarding bit, and then use a combo of routing table and firewall rules to prevent traffic going to eth2 unless it's from the local host.