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New Member

RFC1323 & MSFC2

I've got 6509s with MSFC2 cards doing our layer 3. The MSFC2s are running IOS 12.1(26)

We are seeing horribly slow file transfers from out Windows2008 servers, most of the time large files will fail to copy.

After doing a wireshark sniff it looks like the windowing is going over the 64k limit.

I see that RFC1323 is supported in IOS release 12.2(8) but I don't see that version available for the MSFC2.

My question is. Has anyone else ran into this problem with the MSFC2? What IOS version will allow me to increase the windowing on the router. Am I going to have to upgrade to the Sup720 to get RFC1323 support?

Super Bronze

Re: RFC1323 & MSFC2

I haven't seen your problem, but I wouldn't see why whether your 6509 supports, or not, RFC1323 should have much bearing on other hosts data transfers (unless the 6509, itself, is being used as a host).

Windows 2008 Server (and Vista [and Win 7?]) can default RWIN larger than 64 KB. At least on Vista (and Windows 2008 Server?) there's a command line command, with various options, to control some of the new stack features, including, I believe, RWIN. You might try, if possible, disabling the newer stack features and see if the performance changes.


Some MS references:


Re: RFC1323 & MSFC2

Is this a hybrid 6500 configuration meaning CatOS and then IOS on the MSFC2?

Do you have an SSL Services Module or CCM.

I ask because I think I read somewhere that you'll need the SSL module to support windows scaling larger than 65,535 bytes

This is just some info about SSL module and the support with Sup2 since 7.5(1)