Chris, STP should be enough to avoid these types of problems. In order to cause a bridging loop the station would have to have both interfaces in the same VLAN and forward all L2 traffic except for BPDUs. Even if this were the case the wireless network (10-Mbps?) shouldn't be enough to bring the LAN to its knees (100-Mbps?). If you have STP enabled on all of your switches, I'm doubt that a single station is bringing the network down.
Once you find the offending switch that you need to reboot, you can issue console commands to determine the root bridge and any blocked ports. Make sure that things are normal. You do have your root bridge set manually, don't you? :) To find out which port is causing the loop, take a look at the interface counters. You should see an unreal amount of traffic on the offending port (and the uplink to the core switch). When STP has been enabled I have only come across layer-2 loops twice. Once when a few HP switches had gone bad, and another time when a customer had configured channeling on one side but not the other (3500 series, no channel negotiation). In both cases I found that the problem was made worse with increasing traffic levels, and the problem also revolved around the same set of switches. The channeling problem was a bit more difficult to narrow down though, since it disabled MLS on the core switch and every segment appeared to have problems!!! I hope that helps, - Tom Christopher Dumais wrote: > Hi all, > We are having an STP problem where we think a user with an integrated > wireless and LAN NIC is creating a bridge loop and bringing down the entire > network. The problem occurs then goes away after 20 or so minutes unless we > can narrow down which closet it is coming from and reboot the switch. All of > our management tools die during the outage. Does anyone have any ideas on > how we might prevent this from happening or track down the offender? We have > 6509's in our Core and a mix of 3548's and 3550-SMI. Any thoughts are > appreciated. Thanks! > > Chris Dumais, CCNP, CNA > Sr. Network Administrator > NSS Customer and Desktop Services Team > Maine Medical Center > (207)871-6940 > [EMAIL PROTECTED] Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=70812&t=70797 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
