topic How many switches can be connected in a row? in Switches, Hubs, and Modems

How many switches can be connected in a row?

Josef Müller — Wed, 29 Nov 2006 09:12:37 GMT

Is there a limit or a recommendation how many switches (in my case 2650 and 2824) can be connected in a row?

Is the 7-Bridge-Rule still valid with modern switches?

Thanks in andvance for your answers,

Josef

Re: How many switches can be connected in a row?

Mohieddin Kharnoub — Wed, 29 Nov 2006 23:54:33 GMT

Hi

If you mean connecting in a Chain without loop (Cascading) then you can connect so many (Stacking also can be done up to 15 switches).

The only problem when you have a loop is the maximum number of hops before the BPDU is discarded, and it depends on the Spanning tree protocol version you are using.

In MSTP, its default to 20 (maximum), and in the STP and RSTP that will apply the 7 bridge rule is a "design consideration" that

Good Luck !!!

Re: How many switches can be connected in a row?

Josef Müller — Thu, 30 Nov 2006 08:39:45 GMT

Thanks for the fast answer!

In our Ethernet we use 3 ProCurve 2824 in the server room and several ProCurve 2650 in the office and production wiring closets. The 2824 switches are linked with CAT5 cables. The connection to the 2650s is made with fiber GBICs. We have no redundant links between the switches. We have enabled STP 802.11d.

Does your answer mean that maximum distance between each switch should be 7 links between the switches?

What would happen if the topology excedds the 7 link limit?

If I create a stack from the 3 copper-linked 2824, are they one bridge for STP?

Re: How many switches can be connected in a row?

Josef Müller — Thu, 30 Nov 2006 10:11:23 GMT

For a better understanding attached a schema of our current Ethernet toplogy.

Greetings, Josef

Re: How many switches can be connected in a row?

Jason Scott — Thu, 30 Nov 2006 10:48:19 GMT

Josef that looks fine. The switches in Prod1 are 4 hops away from your spanning tree root bridge therefore they don't exceed the 7 hop rule. All your other switches are less than that.