iproute2 allows to assign MTU per static route , it could solve issues related to different MTU with different destinations example:
https://forum.vyos.io/t/overriding-pmtu-on-a-per-route-basis/10539
it's supported in our system in latest version :
vyos@vyos:~$ sudo ip route add 172.16.100.0/24 dev eth0 mtu 1432 vyos@vyos:~$ ip route 172.16.100.0/24 dev eth0 scope link mtu 1432
The thing is, we don't use iproute2 commands for adding a route. We use FRR staticd for it. As an exception failover route that uses iproute2 commands
FRRouting 8.4.2 doesn't have such option
r14(config)# ip route 192.0.2.1/32 203.0.113.1
<cr>
(1-255) Distance value for this route
INTERFACE IP gateway interface name
dum0 eth0 eth1 eth2 lo veth0 veth1 wg0
Null0 Null interface
color SR-TE color
label Specify label(s) for this route
nexthop-vrf Specify the VRF
table Table to configure
tag Set tag for this route
vrf Specify the VRFCould we use something like Dannil proposes? https://vyos.dev/T4883 , as you said FRR staticd don't allow this option but it could be useful when we have different mtu over the interface.
No, we couldn't.
It is an entirely different case; the routing table can be a number or alphanumeric value when a number is associated with a text value (10, 20, foo, bar)
vyos@r14# set protocols static table 10 description foo [edit] vyos@r14# commit [edit] vyos@r14# cat /etc/iproute2/rt_tables.d/vyos-static.conf # Generated by VyOS (protocols_static.py), do not edit by hand 10 foo [edit] vyos@r14#
So we can use foo instead of table 10 as we associate table 10 with our name in the file /etc/iproute2/rt_tables.d/vyos-static.conf
But all static routes are still configured via FRR and don't use iproute2 commands at all.
The Failover route doesn't use FRR and uses iproute2 commands, so I see only one solution to implement it (add MTU for the failover route).