Forum Discussion

satish_txt_2254's avatar
satish_txt_2254
Icon for Cirrus rankCirrus
May 03, 2018

F5 jumbo MTU

We are building new datacenter and making all network switch run on MTU 9216 in short all my switches running on 10G with jumbo frames.

Question:

I am installing F5 

Big-IP-LTM 10000
and created vPC trunk and i set max MTU size supported 
9198
but does this means all 
Virtual server
i am going to create will run on MTU 9198, is this going to create issue for any public users who is going to access my VIP or any internal datacenter web server who is running on 
MTU 1500
default?

application delivery
BIG-IP
big-ip ltm
LTM
mtu
  • Only1masterbla1's avatar
    Only1masterbla1
    Icon for Cirrus rankCirrus
    May 03, 2018

    In case of Jumbo to standard 1500/1518 bytes MTU, fragmentation will occur. This may cause less than optimal performance. If a host enforces "Don't fragment (DF)" bit to 1, those communication may fail. Usually all devices which support jumbo frames should be segmented from standard frame size.

     

  • Surgeon's avatar
    Surgeon
    Ret. Employee
    May 04, 2018

    If on the client side you are are using jumbo frames and on server side just 1500 bytes mtu, this is not a problem for big-ip, since this is full proxy device. Moreover all network devices come to mtu agreement at tcp 3whs