There is a server I connect to over the WAN and somewhere over the route there is packet loss unless I set the interface MTU to 600:
ifconfig eth0 mtu 600
Doing this causes problems with connections to other equipment. In order to get both to work I tried setting the 600 MTU for the one bad route:
ip route add 10.10.10.0/24 via 10.11.11.1 mtu 600
ip route add 10.10.10.0/24 via 10.11.11.1 mtu lock 600
Then verifying that this is being chosen with:
ip route get 10.10.10.20
But then tests with only the MTU set for a route indicate it isn't going at 600 but as if no change had been made from the default.
Is there any less obvious difference between these methods of adjusting the MTU? Possibly MTU discovery?