Keepalive mechanism about fastd HOT 5 CLOSED

Hi @marek22k,

fastd does have a keepalive mechanism - besides keeping conntrack entries alive, it is also use to detect whether a connection is still alive or if the peer has disappeared. This is not configurable, but done unconditionally.

fastd sends a keepalive packet whenever there hasn't been any (keepalive or payload*) traffic for 20 seconds. After 90 seconds without receiving a packet from a peer, a connection is considered dead and will be reset.

(* in L2TP offload mode, keepalive packets are sent every 20 seconds unconditionally, as the payload packets are handled in the kernel and fastd doesn't actually see whether there is regular traffic)

from fastd.

Then let's not increase complexity by adding configurability where it's not needed :)

from fastd.

Maybe it is possible to introduce a switch with which you can change the interval?

from fastd.

Maybe it is possible to introduce a switch with which you can change the interval?

Would be possible. Do you have the need to switch over to a different peer faster when the connection is lost?

from fastd.

No, fastd works fine for me at 20 seconds (though both peers are public).

Another useful use would also be to increase the keepalive in case you know the Conntrack timeout of the firewall and want to minimize traffic.

For my purposes, the switch would probably be unnecessary.

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