nanog mailing list archives

Jumbo frame Question


From: Harris Hui <harris.hui () hk1 ibm com>
Date: Fri, 26 Nov 2010 08:13:57 +0800



Hi

Does anyone have experience on design / implementing the Jumbo frame
enabled network?

I am working on a project to better utilize a fiber link across east coast
and west coast with the Juniper devices.

Based on the default TCP windows in Linux / Windows and the latency between
east coast and west coast (~80ms) and the default MTU size 1500, the
maximum throughput of a single TCP session is around ~3Mbps but it is too
slow for us to backing-up the huge amount of data across 2 sites.

The following is the topology that we are using right now.

Host A NIC (MTU 9000) <--- GigLAN ---> (MTU 9216) Juniper EX4200 (MTU 9216)
<---GigLAN ---> (MTU 9018) J-6350 cluster A (MTU 9018) <--- fiber link
across site ---> (MTU 9018) J-6350 cluster B (MTU 9018) <--- GigLAN --->
(MTU 9216) Juniper EX4200 (MTU 9216) <---GigLAN ---> (MTU 9000) NIC - Host
B

I was trying to test the connectivity from Host A to the J-6350 cluster A
by using ICMP-Ping with size 8000 and DF bit set but it was failed to ping.

Does anyone have experience on it? please advise.

Thanks :-)

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