Daisy chaining switches

[winstar]

When daisy chaining 2 GigE switches, is there any foreseable advantage to using a 1000BASE-SX SFP module as opposed to just using a copper Gigabit Ethernet port? Distance is not an issue.

The latter operates at the same speed, is cheaper, and eliminates the chance of an SFP failure. I'm thinking copper makes sense, but just wanted to check.

On that same note, how does one determine how much bandwidth the link between the 2 switches should support? Single port for 1Gbps, or EtherChannel for 2, 3, 4, etc.

 

[spidey07]

Makes no sense to use fiber due to the cost of the optics.

Determinig how many links to use = depends. Two is the minimum incase of link/port/cable failure.

 

[p0lar]

Distance or otherwise, Fiber is immune to electrical noise and I can't recall the last time even a SX GBIC or SFP was the cause of failure on a link... you shouldn't be trunking on one link anyway if it's mission-critical, copper, fiber or otherwise! I say GBICs and SFPs are inexpensive, as is quality pre-made fiber cabling (not as much as copper, obviously, but...) -- save your copper triple-speed ports for other devices and keep your trunks looking and behaving like trunks. Plus, fiber gets you cool points with the chicks. (OK OK, *someone* had to offer the other side of this opinion, lol -- rational or not!)

As for determining the number of channels to trunk, just monitor your '95th percentile usage via SNMP for a long enough period of time to catch enough typical volume on the link and make a rational determination as to what's necessary.

 

[cmetz]

winstar, I believe that 1000BaseSX has lower latency than 1000BaseT. In most environments, that ends up not mattering and the cost and headache savings of your cable plant being all-copper wins.

 

[thehstrybean]

I've always used fiber for daisy chaining switches and the such, but copper works if distance isn't an issue and you're sure that you won't have a ton of inteference. I've always had the problem of conduit cable and interference that way, hence fiber.