Redundant link from access switch to core switch

[matthew.norman]

Hello all,

I have set up two link from an access switch to a core switch.

The first link is on int g0/1 of the access switch.

The second link is on int fa0/24 on the access switch.

For some reason fa0/24 is showing as blocked. I assume this is due to spanning tree.

For some reason though if I ping from the access switch to the core switch it uses the port that is apparently blocked.

If I issue a show spanning-tree int g0/1 it shows as forwarding for all VLAN's.

The same command shows int fa0/24 as blocked for all VLAN's.

Is this standard behavior or have I configured something incorrectly?

Appreciate any help.

Matt

[ahmedshoaib]

Hi;

This is the default behavior there is no issue in configuration, to avoid network loop STP block the secondary link. All Vlan those are block on secondary link (F0/24) will be active once your primary link (g0/1) is down.

If bandwidth of both ports is Gigabit, then you can also configure as port-channel which provide you double of bandwidth with redundancy.

Thanks & Best regards;

[Richard Burts]

I agree that based on the limited information provided that it sounds like expected behavior in which a potential loop exists and Spanning Tree has blocked a port to prevent the loop. It would be interesting to know what you are seeing that indicates when you ping that it is apparently using the blocked port.

HTH

Rick

[pwwiddicombe]

If the ports are all in the same VLAN, how do you know it's using the blocked port rather than the Gi 0/1 which is forwarding ?