Duplex settings on an s8700 1

[denflompy]

I understand that the port setting on the Control Network switch must be 100mbps Full duplex but is it possible to administer the ports on the Servers themselves?
Ours appear to be going to Half Duplex on the server side even though they are forced to Full Duplex on the Cajun Switch side.

Any help would be greatly appreciated.
Thanks
Doug

 

[nknook]

Hi Doug,

If you set the Cajun to FDX fixed, and the server is set to autonegotiate (which is default), the server will ALLWAYS resolve to HDX, resulting in duplex mismatch.

This is how the negotiate protocol works.

Actually the duplex isn't "negotiated", but tested by sending a frame on the ethernet TX channel and waiting for it to return on the RX channel. If the frame returns on the RX channel it means the other side is also FDX capable (ie: set to "negotiate"). If you configure a port to be FDX fixed, it will not send back the "testing" frame (because it is not negotiating) resulting in HDX for the negotiating side (because the testing device doesn't receive back the test frame it will asume HDX).

So, if you set one side to be fixed, you *MUST* also set the other side to be fixed. If this can't be done (or if you don't know how), you should leave both sides on auto-negotiate. If for some reason you need to set one side on a fixed speed and duplex, HDX is the safe option.

To answer your question (finally ) : you can set the speed of the S8500/S8700 NIC(s) through the web interface under "configure server". Be carefull, you can break a lot of things there. Also this action is service affecting.

 

[denflompy]

NKNOOK,
I salute you. All fine info. It has cleard everything up. This S8700 is inherited by me and has been set up poorly in the first place. The port settings are wrong (it has ended up at 100/Half on several ports) so I will organise an outage.
Thanks again
Doug