EtherChannel Port Grouping 1

[Niall22]

Hi Guys,

I have a bit of an emergency. My company is expanding our network this weekend and I started setting up the two additional Cisco Catalyst 2950 switches that we need. I have run into some trouble and I'm hoping someone can give me a hand. Our network was intially setup by Compaq and I have just been adding on switches as needed by following Compaq's configuration scheme. We have one backbone switch (Catalyst 3548, I think) that all the other switches connect too using a pair of crossover cables from each switch to the backbone. The backbone switch is configured to use the following command on each pair of ports heading to the other switches: "port group 1 distribution destination". The groups go up to 12 but now I need to add more and can't because their is a maximum limitation of 12. Is there another way of configuring these switches so that they will communicate to the backbone using a pair of crossovers which I'm assuming allows a total of 200 mbps between the switches instead of 100 mbps.

Sorry if this is confusing... I'm in a hurry to get this fixed. I can clarify anything that needs clarifying. Can someone shed some light on my situation??? What exactly is this "port group" command used for and do I need it?

Thanks,
Niall

 

[baddos]

Each port trunk should have their own number. I.e. two cables going to switch a would be "port group 1" and switch b would be "port group 2".

 

[Niall22]

Yes, that is how it is currently set up. But I am now out of port numbers as the IOS seems to have a limitation of 12 and I now have more than 12 switches. Is there another way to configure the switches to function this way?
Niall

 

[BuckWeet]

Yea, with the 3500 switches and lower you're limited to 12 Groups max I believe, The only thing I could think to help resolve your problem would in turn cost more money. The best thing to do would be to probably get another switch and link them together via the Gigabit ports, then that way you could do 6 port groups on each switch or whatever.. That way you could distribute your load.


BuckWeet

 

[Niall22]

I guess we'll have to look into getting another 3548 or similar. Thanks for your help guys.

In the mean time, I can still run one crossover from each switch to the 3548 without using port grouping, right? Would we notice much of a difference?

Thanks again,
Niall

 

[BuckWeet]

I highly doubt you'll notice the speed difference, unless you're running some high bandwidth apps...


BuckWeet

 

[baddos]

I'd recommend using something other than a 3548 for your backbone switch. It doesn't have the forwarding capacity as the 2950-48 and nowhere near the 3550's.

The 3548 was intended for a wiring closet to connect end-user workstations and not to connect your switches together.

-Bad Dos

 

[Niall22]

It wasn't my decision. This was done by Compaq before I started working here. Guess they don't know much networking. I am assuming that Cisco had some input into the design though since they would have had to go through a RFP process in order to get the contract which would have been fairly big since it covered many offices. They are replacing all of our switches in September and they told me that they might Hewlett Packard switches now since Compaq has merged with HP. Hope they are decent beause the Cisco equipment has been good for us.

Niall

 

[baddos]

The HP switches are nice too. I wouldn't worry about them. I have had good experiences with them. It's 3com that you have to look out for. :-(

 

[BuckWeet]

HP and Cisco have ties, I've heard things that Cisco makes HP switches (Cisco rep told me this).. They do have ties though, becaues HP switches support things like CDP..


BuckWeet

 

[Lequang]

Why dont' you use stackable switch (cisco or Nortel). This allow to expand your number of ports.
Network devices should always be independant of PC/servers brand.