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  • 1.  Fabric Fragmentation and MTU

    Posted 06-25-2019 11:20
    Hi All,

    I would like to know how the fabric fragmentation works and how a network-interface MTU configuration affects this feature. 

    Currently I have a LAN and WAN interface for 2 routers which peer with each other. LAN MTU on both interfaces are configured as 1600, and WAN is configured as 1500 (left as default). When I enable path-mtu-discovery for the neighborhood used to facilitate the peering, I get a maximum path MTU of 1998. 

    In this case, does the network-interface MTU get overwritten for traffic between these two peers? Technically if I generate traffic on the LAN side of router-1, destined for a service on the LAN side of router-2 (with DF bit set), I should theoretically be able to send 1600 byte packets end to end, correct? 

    Also - is there something I need to enable in configuration for path-mtu to be taken into account, or does that happen automatically? 


    Morne Vermeulen
    Core Engineer
    +27 (0) 10 141 8512

  • 2.  RE: Fabric Fragmentation and MTU

    Posted 06-25-2019 13:22
    Hey - This is answered in this thread.

    Victoria Smiley