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New Member

Cascading 2950 switches

I should be grateful for some advice on cascading 2950 switches with GigaStack GBIC.

The documentation I have found on the Cisco web site states that when the switches are connected in a cascade stack the links operate in half-duplex mode.

My switches show to be operating in full-duplex mode. The IOS does not allow you to change the duplex speed.

Is this correct, and is there any new links to sites that I may view regarding configuring gigabit stacking.

Thanking you in advance



Re: Cascading 2950 switches

As long as you have stacked no more than two switches, they are operating in full-duplex mode. Adding a third and consecutive switches will cause the entire stack to switch back to half-duplex mode.



New Member

Re: Cascading 2950 switches

Thank you for your reply

I have tried cascading 3 2950 switches together, the gigabit interfaces still show full-duplex and autonegotiate.

However when I add a 3524xl, this switch does go into half-duplex.

Any ideas.

Your assistance is much appreciated.



Re: Cascading 2950 switches

Hi Andy,

How did you cascade them? I assumed that you were using one GBIC per switch, this is different from using one GBIC per connection. In the latter case you would indeed get two full duplex connections.

We have the same stacks here also, both with 3524 and with 2950's.

I just checked that the 2950-switches are indeed in half duplex mode.

They are.

New Member

Re: Cascading 2950 switches

Hi Leo,

Thank you for your reply.

I have set up the 2950s as shown in the cisco diagrams with port 2 of one GBIC connected to port 1 of the GBIC on the next switch, and GBIC port 2 of that switch connected to GBIC port 1in the next switch, ending with a redundant link to the top switch.

I have read the documentation again, and I fear I may have misread the document. When it says the cascade stack operates in half-duplex mode, I assumed they meant the Gigabit connections between the switches, and not the fastethernet ports. I have indeed checked the fastethernet ports which are working at half-duplex (Gigabit interfaces still show full duplex).

Am I reading the document right this time, and is this how it should be.

If this is the case I apologise for wasting your time, and thank you for your time and effort.



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