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New Member

MDI/MDI-X on Ethernetmodules in Cat6500, Sup720, IOS

Hi all,

I'm looking for informations about MDI/MDI-X on the Ethernetmodules for the Cat6500 with Sup720 and IOS.

For the Cat6500 with CatOS I can find this information in the release notes of the software.

But there is nothing for IOS at least nothing I can find on CCO.

Perhaps someone has this infos and can give it to me.





Re: MDI/MDI-X on Ethernetmodules in Cat6500, Sup720, IOS

Hello Udo,

I have found information on "mdix auto" in both the release notes and the command reference for 12.2SX for the sup720.

I hope this resolve your question.


* Please rate useful posts.

New Member

Re: MDI/MDI-X on Ethernetmodules in Cat6500, Sup720, IOS

Hi Leon,

thanks for the link.

But there is a reason for my question.

I have a WS-X6548 where MDI/MDI-X is working with fixed speeds configured. With a WS-X6748 this doesn't work.

On this board it works only when the ports are set to auto.

In the release notes for CatOS there are remarks that this is a normal behaviour.

But I can not find this for IOS.

So, I'm looking for general informations about the MDI/MDI-X behaviour of the several ethernet boards for the Cat6500 with IOS.



Re: MDI/MDI-X on Ethernetmodules in Cat6500, Sup720, IOS

Hi Udo,

WS-X6548-RJ-45 and WS-X6548-RJ-21 both supports MDI/MDIX wit sup 720 running IOS

But there are some caveats

1) If you enter the mdix auto global configuration command, WS-X6548-RJ-45 and WS-X6548-RJ-21 Ethernet ports that are not configured to negotiate the Ethernet speed might not pass traffic. (CSCee07738)

2) The WS-X6548-RJ-21 module does not support the mdix auto command. This problem is resolved in Release 12.2(17b)SXA. (CSCec50648)

Check this link for caveats

Check this link for features on these cards

HTH, if yes please rate the post.