Cascading layer 2 switches

jouellet · ‎06-16-2008

Hi,

We have a campus designed network that have a core level: 10720 routers on a ring topology, a distribution level: 3750 switches with ip routing, and an access level: 2950,2960,3550 POE and 3560 POE layer 2 switches. I want to know how many switches can I link together on my access layer. What is the maximum level that I can cascade layer 2 switches: 2,3 or more?

i.e distribution 3750----2960---2960---and so on.

Thanks

scottmac · ‎06-16-2008

Stringing switches along like that is against Best Practices because it generally creates a massive bottleneck (all that downstream bandwidth aggregating and trying to squeeze out of the top switch's egress) and frequently creates a chain of single-point(s)-of-failure (regardless of Layer 2 or Layer 3 architecture).

It's just not a good idea; avoid it at all costs.

Good Luck

Scott

Collin Clark · ‎06-16-2008

As Scott stated, don't (over) do it! Two is the most I would recommend. You may have to manipulate spanning tree too, so it may also depend on your knowledge level.

Hope that helps.

ohassairi · ‎06-16-2008

you can go until 7 cascaded switches by STP

http://www.cisco.com/en/US/tech/tk389/tk621/technologies_tech_note09186a0080094954.shtml#default