No. of Access switch in a stack for IPT

[iptuser]

I understand that there is a recommendation to only stack 2 access switches due to the Half Duplex/Full duplex issue when used with IPT. Can any one provide any documents on this

thanks

Wayne

 

[jneiberger]

What does per port speed and duplex have to do with the number of switches in a stack? Can you elaborate?

 

[ADB100]

The issue you describe is to do with the Stacking GBIC's Cisco sell that allow you to create a BUS-type connection between more than 2 switches (i.e. 3 or more). This only occurs if you don't have point-2-point connections between switches (the stacking GBIC has 2-ports and allows you to link it to 2 other switches making it a non point-2-point connection and it then runs half duplex).

I would suggest reading some of the best practises - don't stack switches unless it is using 3750's where it creates a logical switch as opposed to 3550's (3560's etc) where you STACK using Ethernet and it all goes to sh*t with regards to STP.

HTH

Andy

 

[jneiberger]

Oh, now I see what the OP was referring to. I misunderstood. That's good info to have about the 3550 and 3560. But the 3750s are PRICEY! We get a pretty hefty discount on Cisco stuff and they're still outrageous.

 

[ADB100]

I would still not 'stack' switches using Ethernet if possible. My philosophy would be 1-switch, 2 VLAN's (Voice & Data) and 2 Trunk-uplinks to your Distribution-Layer devices (2 of). Beyond the Distribution Layer it should all be Layer-3 anyway so a routed 2-core model etc.

To be honest I am surprised there isn't some clever spreadsheet floating about that lets you add in the number of access-ports required, number of wiring closets etc and works it all out for you. Saying that though, I get paid for this so if you want me to put a design together for you I'll give you the telephone number for my boss.........

Andy