Quick Cisco question

iaind · 1 Mar 2010 at 15:57

Quick question - what's the reccomended approach to provide rendundancy on uplinks (configured as VLAN trunks) on non stackable Cisco switches (3560s specifically)?

Can I just plug the uplinks in a "loop" and let the switches figure it out, or is that asking for trouble?

iaind · 1 Mar 2010 at 17:08

So if I've got

Switch 1
|
Switch 2
|
Switch 3

Lets assume the uplinks are all on port 1 of each switch

If I added an uplink from switch 1 to switch 3, using port 48 on both - I'd add "switchport backup gi0/1" to port 48 on both switch 1 and 3?

iaind · 1 Mar 2010 at 17:09

bigredshark said:
Word of warning, for some unknown reason it requires fairly recent switches and IOS - 2950s don't support it for instance, odd considering it's simplicity but that's the way it is...

Ours are 3650s with 12.2(25) and a single 3750 with 12.1(19)....good enough?

iaind · 1 Mar 2010 at 18:14

Ah, so the backup line is saying "port x is my backup" not "I'm a backup for port x"?

Basically switch 3 is my server switch (thats the 3750), 1 and 2 are both desktop switches - I want to ensure users on switch 1 can access the servers if switch 2 fails.

iaind · 1 Mar 2010 at 21:46

That makes a lot more sense!

I could then just move the uplink that goes between 1 and 2 to 3

Don't think etherchanel will be worth it for me, the odds of a single cable/interface failing is pretty remote and I wouldnt benefit from the extra bandwidth - the desktop switches just run SCCP voice and ICA sessions, even with all 48 ports at full pelt, I doubt I'd come close to the limits of a single gbit uplink.

Sometimes it does just take another pair of eyes to spot the obvious solution