ip mtu vs mtu vs mpls mtu
This is kind of a stupid question, but I've read the definitions several times in several places, and I'm just not sure I'm getting it, so can somebody please confirm.
ip mtu -- only ip packets (not MPLS)
mtu -- maximum size of ANY packet sent on the link, including MPLS
mpls mtu - the maximum size of IP + MPLS lable
So, if I want to send a 1500 byte IP packet with 2 MPLS labels on it, on a fast-ethernet interface, and I don't want fragementation then:
mtu = 1508 (Or anything larger than this, up to the interface maximum for jumbo frames - 1530 or so.)
mpls mtu = 1508
ip mtu = 1500
Or I can just set the mpls mtu to 1508, and it will automatically up the mtu value...
Thanks to anybody who can help with my confusion.