[j-nsp] J6350 Jumbo frame MTU and OSPF setting

[Ben Dale]

Hi Harris,
> However, increasing the MTU size on both the J6350s may not be able to get a better TCP throughput, because the Host NICs and Switchport are also using MTU 1500 right? Should I change the MTU size on Host NICs and Juniper EX switches to MTU 9018 in order to prevent the frame fragmentation happened below 9018?
> 

There should be no more drops if your end devices are 1500 MTU and the "core" network is 9018.  As for your throughput, that is a little harder to calculate, but the figures you are quoting seem quite low even with 80 ms latency. 

Latency aside, you should be able to easily saturate a 100Mbps pipe with 1500 byte frames on a J6350 without issue (in terms of PPS).  I don't believe adjusting the MTU size is going to make that much difference, but it is worth trying.  I would be inclined to kick off iperf with a UDP test with 1500 byte frames to see what throughput you can get out of the pipe first, then start investigating TCP/MSS issues.

Cheers,

Ben