What is the recommendation for setting MPLS MTU when the hardware does not permit the setting of the interface MTU:
PE-Edge-2(config)#int fastEthernet 0/0
% Interface FastEthernet0/0 does not support user settable mtu.
The MPLS MTU could be changed with "mpls mtu 1524", but this gives the error:
PE-Edge-2(config-if)#mpls mtu 1524
*Dec 24 20:54:43.467: %TFIB-3-MPLS_MTU_SET: Setting mpls mtu to 1524 on FastEthernet0/0 which is higher than the interface mtu 1500 . This could lead to packet forwarding problems including packet drops.
Is it permissible to set the MPLS MTU greater than the interface MTU, as I thought that MPLS packets cannot not be fragmented, but rather simply dropped?
In this scenario, is the only solution to limit the size of inbound packets with something like "ip tcp adjust-mss 1476" to avoid any potential packet drops?