Switch Stacking

[git]

Hello out there! I have to do some research on switch stacking and I can't seem to find any info out there on the net. any futher help with resorces would be most helpfull, along with any tips tricks that some of you may know or have delt with this topic. Please note I have checked on google, and all I could get were prices on switches and what not. If this is a really green/newbie question im sorry, I am new to this stuff

[mmelby]

It really depends on the switch. With 3com on the manageable switches there is a special connector on the back that will connect the backplanes.

On Cisco you "usually" need to trunk the ports that you will use to connect the two switches. On some models the have special ports for this function.

On most low end switches there is sometimes and X port to stack 2 together. If there is not you will need to make a crossover cable.

[clesius]

Hey,

We have about a dozen 3COM Superstack III 3300 Series switch here and it's working great. Since our office is on multiple floor and cable is really not an easy task here, we have a stack of 4 switch on one floor with each switch having a 1GB port to connect the other floors stacks.

So each stack are linked together by gigabit connection and each switch within a stack are connected together using the 3COM Stack cable which uses a special connector in the back of these switch.

[t2k2]

I am not sure I understand this question. I understand how multiple Cisco switches are linked in some manner and Spanning Tree Protocol is used to prevent a broadcast storm, but what exactly does "Switch stacking" mean? I am sorry, I'm pretty new to this also, but I think the replies that you more experienced AO members post to this thread may help me out also. If anyone has a good link on this, that would be great. I have had the same misfortune as git with the searches for information on the topic.

Thanks

[ammo]

Stacking usually referes to grouping multiple switch into "one big switch" with a shared backplane (not limited to a single port's bandwith (100 or gigabit)) with (often) proprietary interconnects.

Cascading usually referes to uplinking switches/hubs on normal ports (or uplink ports which really is the same as a normal port) in a dasy-chain style with effect of creating bottle-necks (due to uplinked ports limited bandwith (100/1000)).

Which one did you mean Git?

Ammo

[t2k2]

Thanks for the clarification on that ammo. That helps.

[zaggy]

OK this may be so not what you are looking for but I found one url....

http://www.cisco.com/warp/public/cc/...t/swclu_ov.htm

[v_squared_over_]

One other important consideration in stacking switches (at least with normal and uplink ports) is the Rule of 3. In most switches I've encountered you can only stack a total of 3 switches. Anymore and the TTL counters will get too low and packets will wind up getting dropped. Also, unless you have a gigabit uplink port, this can have a noticably detrimental effect on bandwidth.
Still, other switches I've heard of will at least let you connect more than three switches depending on the total number of RJ45 ports on them. I hope this helps.

v_squared_over_r

[ammo]

v_square: that's not stacking, that's cascading (also called dasy-chaining).

Ammo