[SOLVED] Set MTU on LAGG interface



  • Hi!

    Running pfSense 2.3.1, with a single LAGG (LACP) with 2 member interfaces, and a whole bunch of VLANs on top of that LAGG.

    After searching the forums, and trying some google-fu, I still can't for the life of me figure out how I'm supposed to set the MTU of the LAGG?

    If I try to set the MTU through the child VLANs, it gives me the following error:

    The following input errors were detected:
    The MTU of a VLAN cannot be greater than that of its parent interface.
    

    Which is perfectly logical, but then, how do I change the MTU of the parent?

    There is no option for it under Interfaces > (assign) > LAGGs, and you can't do anything to an unassigned interface through the GUI, but you need an unassigned interface to create a LAGG… So yeah.. I'm stuck.

    EDIT (SOLVED):
    Well.. that was embarrassingly simple, though not very intuitive if I'm honest.

    What I had to do was to actually go ahead and assign the LAGG, and from there I could set the desired MTU.

    I just find it a bit odd to have to "assign" a LAGG interface, just to be able to configure the actual interface, considering it has it's own dedicated tab under "Interfaces" called "LAGGs"…

    PS: On a side note, after enabling the jumbo frames MTU (9000), I also had to adjust "kern.ipc.nmbjumbop" and "kern.ipc.nmbjumbo9", as per:
    https://forum.pfsense.org/index.php?topic=89087.0


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