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6509 connectivity problem

Hello All,

Very recently , we have introduced second 6509 on our Network for Redundancy & Load Balancing function. The Switches in Remote locations (3548 with GBIC Uplink ) have connections to both 6509's . we have made second 6509 as Root Switch for some of the Vlan's . Now the users connected in root Vlan's of second 6509 are experiencing problems . For example , when they ping any server or printer , after 20 or 30 Requested timedout , it replies back and printers also the same case . Occasionly , We have to restart the printers to get the Network connectivity . Sometimes users connected in same Vlan can't able to ping each other or sudden loss of Network connectivity while working . What could be the problem?

Many Thanks in advance.


Community Member

Re: 6509 connectivity problem

It sounds like you haven't changed any port costs. One thing you might want to try is changing the port costs on the switch interfaces pointed towards the root switch. If not you could just be experiencing long convergence from all the spanning tree events. If you watched the switches you would probably see them constantly switching between blocking and forwarding and never really stabilizing. Make sure you fully understand the spanning tree algorithm. Any discrete math book should explain it.

Hope that helps.


Re: 6509 connectivity problem

Where are the gateway routers for these vlans? Are the 6509s running msfc's? Is the router for the vlans that are using the new 6509 on that switch or still in the old one? Is there a full trunk (all vlans) between the two 6509s?

Community Member

Re: 6509 connectivity problem

Sounds well. What we did was , for some of the Vlan's we made 2nd 6509 as root Switch , but we did not set any port cost . How to set the port Cost ?. Is there any configuration change required at edge Switch level (3548) ?.



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