stack and trunk on 4108 and 2524

[Anonymous]

Good Morning,

I would like to put in place a stack with a HP4108gl and a HP2524. I have two questions:
1. If I have to reboot the HP4108gl (the commander) What will happen on the HP2524?
2. Can I put in place a trunk with one port Gb LX on the 4108gl and one port Gb LX on the HP2524?

Thank you for help...

[Arimo Laine_2]

Hello.

1. Nothing. Rebooting commander causes the commander to go down, for the member switch it's business as usual.

2. You can, but why bother? HP port trunking is a link aggregation method, so it makes sense only if you have a minimum of 2 coterminous links you want to connect between the switches. I.e. if you have 2 LX connectors on both switches and you want to have a 2GB link between them, then you create a trunk with these two fibers. The links must be same type of media, so trunking TX with Fiber is a no-go. Similarly, both links must be on the same device, i.e. 2 links trunked between switches, but not so that 1 switch has a trunk of 2 links which end up in different devices.

HTH,
Arimo

[Mark Landin]

Before you do this, be sure you have the latest firmware on the 2524's. It's F.05.09, I believe. Older firmware had numerous bugs related to stacking and management.

We stacked some older 2524's with two 4108gl's we have. Things were fine until we put the G.07.21 firmware on the 4108's ... then we began seeing some very odd traffic interruptions. Finally we took the 2524's out of the stack and the problems disappeared. We now have two stacks ... one with just 2524 switches, and one with just 4108s. (The switches are still connected via Gigabit-SX ports, but they are in separate management stacks).

[Anonymous]

Thank you for all this advises and informations.

About the 2524, finally we will put in place stack with two 4108gl so I hope we will not have problems...

In fact, we will have two stacks with two HP4108gl in each stack. This two stacks are connected with two fibers GB LX. In fact I would like two put one fiber in each HP4108gl so in case of crash, I will have one of the link up...
I do not like spanning tree so I would like to put in place trunk to have more performances... Is it possible?

Thank you in advance

[Mark Landin]

OK well when you say "stacking" I'm thinking we are talking about different things.

Connecting switches together over gigabit or 100Base-T or even over the special "gigabit stacking kit" is not the kind of "stacking" I'm talking about... I'm talking about the stacking you do in the management interfaces, so that you can assign 1 IP address that will apply to mutiple switches. THIS is the kind of stacking that we saw problems with.

SImply hooking the switches together isn't a problem. Trying to put them all in the same management stack caused odd things here.

[Arimo Laine_2]

Hi.

A trunk can be done like this:

Switch 1
2 cables
Switch 2

It can not be done like this:

_Switch 1__
Cable Cable
Sw 2 Sw 3

Does this make it any clearer?

HTH,
Arimo

[Anonymous]

Thank you,

In fact, I would like to put in place this topology:

Sw4108gl1-----------sw4108gl3
Sw4108gl2-----------sw4108gl4

The HP4108gl 1 and 2 are connected with a stack kit and the 3 and 4 with a stack kit to. the "----------" are two fibers LX Gb.

In this case,if I have understood, I can't put in place trunk on the two Gb links ... So how can I stop loops ? using spanning tree?

Thank you

[Arimo Laine_2]

Hi again

STP is here the only way to stop loop. If you configure switch 1 to be your STP root switch, the link will be blocked either between switches 2 and 4 or 3 and 4.

HTH,
Arimo

[Anonymous]

Hi,

Like you said, I have found the solution in the RSTP documentation to my problem. Now just have to put in place ...

Thank you again