Yes some access ports were portfast! Silly me! If any of those access ports are in port fast does this mean that spanning tree will not work properly? I know portfast will put the ports into instant forwarding mode but it should still receive bpdus in order to make a decision on what ports are blocked / forwarding yes? Or because they are forwarding straight away it doesn't listen to these bpdus in order to make this decision.
Cheers, Aaron. -----Original Message----- From: Ben Steele [mailto:[EMAIL PROTECTED] Sent: Friday, February 01, 2008 2:08 PM To: Aaron R Cc: [email protected] Subject: Re: [c-nsp] Spanning-Tree question Do you portfast enabled on those access ports? On 01/02/2008, at 3:31 PM, Aaron R wrote: > Hi Guys, > > > > Ive got a problem that I am hoping someone can have a look at. I > currently > have four 3750's. Two belonging to one business unit and two > belonging to > another. Each group of switches is running a separate VTP domain / > VLAN > database. > > I am running PVST however when I connect the final link between the > four > switches there is a loop and spanning tree doesn't block any of the > ports. > Would anyone have any clue as to why this would be happening? Could > it have > something to do with the link between the Business units being on > separate > VLANs? We don't want the possibility of VLAN corruption occurring > hence the > different VTP domains. Currently I am shutting down one of the > uplink ports > to Business A to remedy this problem. Please see the diagram below. > > > > Cheers, > > > > ------------------------ > ------------------------ > > | 3750 Switch 1 |------- Trunk ------ | 3750 Switch 2 | > > | Business A | | Business A | > > ------------------------- > ------------------------- > > | VL 50 | VL 50 > > > | | > > | VL 100 | VL 100 > > > ------------------------ > ------------------------ > > | 3750 Switch 3 |------- Trunk ------ | 3750 Switch 4 | > > | Business B | | Business B | > > ------------------------- > ------------------------- > > > > > > Aaron. > > > > > > _______________________________________________ > cisco-nsp mailing list [email protected] > https://puck.nether.net/mailman/listinfo/cisco-nsp > archive at http://puck.nether.net/pipermail/cisco-nsp/ _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
