Strange VLAN Behaviour

Unanswered Question
Feb 1st, 2008
User Badges:

Hi Folks,

Appreciate any help on a Vlan issue.

Basically have a vlan configured on a MSFC

Have a number of machines connected to switchports in this vlan. When we power up the machines they can not connect to anything outside the vlan. Machines get IP's via a helper address and can ping the default vlan gateway. After roughly 15-20 minutes, comnnections are allowed out. I have no ACL blocking in place. This happens everytime we power the machines down for a while and restart. There is nothing local on the machines blocking connections (firewall,AV), I have tried various builds and it makes no difference. The switchports are only configured for access to the said vlan. There is no issue with spantree or portfast settings. Help

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
Kevin Dorrell Fri, 02/01/2008 - 04:05
User Badges:
  • Green, 3000 points or more

Are you using port security on that VLAN?

Also: check the consistency of the MST-VLAN mapping on all the switches you have, and check the VLANs allowed on each of the trunks - they should correspond to whole sets of MST instances, nothing less, nothing more.

Kevin Dorrell


scuzzlightyear Fri, 02/01/2008 - 06:06
User Badges:

Not using port security, using an old version of catos on the 6500, doesn't have the spantree mst command

Kevin Dorrell Fri, 02/01/2008 - 06:17
User Badges:
  • Green, 3000 points or more

I'm sorry. What on earth made me think we were dealing with MST? It must be Friday again!


This Discussion