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VLAN problem CatOS

We have several 6509 switches in a building that use 802.1x authentication. It automatically assigns users PCs to different VLAN according to their certificates. Several days ago, VLAN 102 users couldn't communicate nothing, they couldn't ping each other nor the gateway. Strange thing is other VLANs on the same 6509 worked fine and all VLANs worked fine on other 6509 switches. I checked the authentication log and noticed the user past authentication on VLAN 102 so it's not an authentication issue. I verified trunk, spanning tree and VTP, no issue. It appears to be a hardware issue, however, I replaced almost everything but problem still exists. CPU utilization is low, traffic volume is low. The worst part is it's intermittent. Any suggestions? Thanks.

2 REPLIES
Silver

Re: VLAN problem CatOS

check out the following troubleshooting link, see if it helps :

http://www.cisco.com/en/US/tech/tk389/tk213/technologies_tech_note09186a0080176720.shtml

Silver

Re: VLAN problem CatOS

This smells of a spanning-tree problem. Im thinking along the lines of a user created loop, such as through a hub or Windows XP wireless bridging.

Have you enabled portfast on all user ports?

If so, have you enabled bpdu-guard?

What about the other spanning tree tools such as loop-guard and root-guard?

What spanning-tree protocol are you running STP or RSTP?

Please rate all helpful posts.

Brad

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