Sounds like a STP loop, a guess; when you put the 3550 a different root bride is elected. Spanning tree disabled somewhere on the old layer 2 device?
-Todd ""Firesox"" wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > Folks, I have an urgent issue. > My customer has network consists of about 20 sites. There are two hub sites > and each hub hosts sites each. > Some routers are configured to bridging as well as routing. > I am replacing all the hubs at one of remote sites with all 3550 SMI > switches. I know there is no physical loops. > The router at the site is 2610 with T1 CSU module. The problem is as soon > as I plug in the 3550SMI into the ethernet port on the router, > the whole network crashes. I can run the remote site's LAN(1 MDF and 5 > IDFs) thru Gig backbone just fine. > I noticed as soon as the router gets connected to the 3550, serial link(T1) > starts flapping and will go down after a minute or so. > The router is configured to route and bridge. I have tried most basic > troubleshooting such as checking for physical loops, hardcoding the switch > port to 10mb half duplex, etc... > I even tried to connect the router to just one 3550 smi with no other > connections, and the entire network crashes. > Has anyone seen a problem like this? Unfortunatelly this network is > 24x7x365 facility and I only had 10 minutes to troubleshoot the problem. > I could use some input on this. > > Thanks in advance. > firesox Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=46382&t=46326 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
