topic Re: Duplex Mode-Force it or Auto in Network Security

Duplex Mode-Force it or Auto

paulc — Mon, 11 Mar 2019 10:42:08 GMT

I'm getting a lot of late collisions. The internal int is set to AUTO. It's connected to a Dlink unmanaged switch. Sh interface command is showing the interface at half-duplex. I"m thinking of switching it to 100FULL. Is it normal for the PIX interfaces to be set to AUTO? Also if it's set to AUTO, why would it only negotiate a half-duplex link when the DLINK is capable of FULL?

Re: Duplex Mode-Force it or Auto

Fernando_Meza — Tue, 10 Jul 2007 00:35:25 GMT

Hi .. assuming the PIX's interface you are talking about supports 100 FULL. Then you could hard code it and test it if you like. Sometimes the auto feature does not neccesarilly negotiate correctly. I have found this specially with some old NICs. In which case it is a good idea to hard code in both ends.

I hope it helps .. please rate if it does !!!

Re: Duplex Mode-Force it or Auto

paulc — Tue, 10 Jul 2007 11:34:46 GMT

Thanks, Fernando. Guess I'll switch it and see what happens!

Re: Duplex Mode-Force it or Auto

pdriscoll — Tue, 10 Jul 2007 19:21:27 GMT

Hi Paul. I recently ran into the same issue with late collisions, duplex negotiating to half, spped to 100mbs. I found if I set the speed to 100 mbs (do not use auto), and then set the duplex to full, the duplex setting stayed configured at full and experienced no more late collisions.

HTH.

Patrick

Re: Duplex Mode-Force it or Auto

paulc — Thu, 12 Jul 2007 15:31:44 GMT

Thanks, Patrick. It sounds like you experienced the exact same as what I am seeing. I plan on making the change in the next couple of days.

Re: Duplex Mode-Force it or Auto

paulc — Fri, 13 Jul 2007 10:12:53 GMT

I reset the int this morning and cleared the couunters, also. Looks like that was problem. Collisions, including late, were at zero last time I looked whereas before the late were accumulating quickly. Thanks, everybody!