Jumbo Frames and Flow Control across a WAN Link.

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Jun 14th, 2007
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All, on our LAN we have Jumbo Frames and Flow Control enabled for our ISCSI SAN. We are wanting to replicate data from SAN1 to SAN2 across the WAN on an MPLS line. Do we need to enable jumbo frames on our MPLS routers to, or is jumbo packet removed when it goes across the router?

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balajitvk Thu, 06/14/2007 - 09:58
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The ability of the various Catalyst switches / routers to support various frame sizes depends many factors, including the hardware and software. Note that certain modules can support larger frame sizes than others, even within the same platform. Additionally, maximum frame size support can also change depending on the software version you use.

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paolo bevilacqua Thu, 06/14/2007 - 09:59
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Which router do you have? Only certain gigabit interfaces can support jumbo frames. Then, you have to ask your MPLS provider if they will carry them on their network.

rwamstutz Thu, 06/14/2007 - 10:02
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we have a 2801 on one end and a 3800 on the other.

paolo bevilacqua Thu, 06/14/2007 - 11:11
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The 38x5 does support jumbo frames, but the 2801 does not. So you are limited anyway.

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