Hello
I have one organization which have about 1000 systems.we have one manageable switch and many unmanageable switches.all our computers are connected to un manageable switches and unmanageble switches are connected to manageable switch.My manageable switch is connected to providors switch.In peak usage the switch ports on providor are get fequently blocked.Pls give me solution to prevent ports blocking problem.
Sounds like you are experiencing some STP-related problem. Disable STP for your uplink ports to check out if this is the case. If so, *resolve* the problem and *reenable* STP for these ports.
Spanning tree problems on unmanaged switches?? I suppose that is possible, but when I hear of a site with 1000 systems and only one managed switch, I tend to think "low budget, old equipment" that probably does not handle spanning tree.
My understanding is that his one and only managed switch does have upstream ports which tend to change into "BLOCKED" state (hence the STP guess). Surely possible that I am wrong.
The OP's question was unfortunately unclear. I replied at greater length to the multiposted copy in comp.dcom.sys.cisco . I did not think of "blocked" in the spanning tree sense; my thinking was more along the lines of traffic being dropped due to congestion.
I had a problem with a port becoming blocked regularly on a Cisco switch. It was caused by too many collisions. The problem was, my workstation was set to full duplex, and the switch was half duplex. Could you have a similar problem?
Bert
So there are some low cost switches that don't even run spanning-tree ... scary. I would have thought that even if the swicthes don't let you manipiulate spanning-tree it would at least be there in its raw 802.1 format.
BernieM
Is it the switch ports on the managed switch that are getting blocked or on others? Can you debug spanning-tree on the managed switch to see how it's reacting?
What are the makes and models of switches? Can you give us a topology map and some indication as to which ports you suspect are getting blocked. What are the symptoms exactly?
BernieM
Old switches, and even modern consumer-level cheap switches, often treated the BPDU packets as regular layer 2 packets, to be passed through transparently.
It'll be helpful if you provide some more information.
- Laurent
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