Connecting 2960 to other switches

Unanswered Question
Sep 10th, 2009

I have a new 2960 switch that I am trying to connect up with some other switches that are already in place.

The switches that are already in place are located in my server room, and the new 2960 I am trying to hook up is in my office. I patch the jack in my office that I am plugging the 2960 in to to a switch in the server room with a straight through cable. Then on the 2960 I plug it in to the jack in my office with a straight through cable then plug my PC into the switch but I get no connection.

Then after trying to go through the switch and it not working it seems as though it disables the port on the switch I am using in the server room. If I unplug the switch in my office then plug my PC directly to the jack it says I have no network connection.

Do I need to run a cross-over cable from the patch panel to the switch in the server room? Then a straight through from the 2960 in my office to the jack? And would doing this wrong for some reason disable ports on the switch?


I have this problem too.
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Edison Ortiz Thu, 09/10/2009 - 07:00

It sounds like the switches in the computer room have bpduguard enabled on host facing ports.

With that feature enabled, a switchport will go into errdisable once it receives a bpdu from a device.

You must disable this feature if you want to connect your switch to your production network and remember to enable it once your project has been completed.



wjstclair Fri, 09/11/2009 - 05:00

Thanks for the response that sounds like the issue. Once the port goes to errdisable do you have to manually re-enable or does it re-enable itself after a certain amount of time?

Thanks again!

Leo Laohoo Sat, 09/12/2009 - 17:08

Depends on the configuration. If you enable BPDUguard, you need to shut/no shut. There's a command in the global configuration to re-enable err-disable ports.

YANGCCIE4 Sat, 09/19/2009 - 09:33

once the port in the errordisable status,

default that interface by issue command, defa int fx.x, and sh/no sh ,


YANGCCIE4 Sat, 09/19/2009 - 09:21

Hi, wjstclair

I am not sure if 2960 has the STP function, or port-security function,But you are better to check it out, if the switch port in your server room being configured with the port-security command, or the spanning portfast command

Interface mode

sw1#sh run int f0/11

Building configuration...

Current configuration : 165 bytes


interface FastEthernet0/11

switchport mode access

switchport port-security maximum 2

switchport port-security

switchport port-security mac-address sticky


Or the globale configuration mode

# spanning-tree portfast bpduguard default

these command will limit or prevent your new device or non-single host device plug in.

Also,think about the cross-over cable might be a good choice to connect two switch, if the ports could not self-adjust the cable connection,

Also, think about the interface parameters such as mtu, bandwidth, and delay, duplex, and speed.

that is all i could think out.

hope this help



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