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5500 STP query

Martin Tighe
Occasional Contributor

5500 STP query

Hi I have some 5500 switches, I have primary and secondary WAN connections going into ports 1 and 2. I can not seem to be able to make port one 'the root' port which is the primary, and cant find out how to make port 2 the 'alternative' port.

 

Also should I turn on loop protection for both ports or just one?

 

If I do a display stp bri, here are the results...

 

 MSTID     Port                   Role  STP State    Protection
   0     Ethernet1/0/1            DESI  FORWARDING     NONE
   0     Ethernet1/0/10           DESI  FORWARDING     NONE
   0     Ethernet1/0/11           ROOT  FORWARDING     NONE

 

Would this be enough to provide failover protection in the event of a loosing one of my wan connections?

 

Thanks in advance

3 REPLIES
mnantel
Advisor

Re: 5500 STP query

Missing some data here, but why would your primary and secondary WAN connection be desirably root?

Most service providers do not send STP BPDUs.

The root port will point towards the bridge with the lowest STP bridge ID, which is composed of admin priority in the most significant bits and the bridge MAC in the least significant bits, all of that within each MST instance. In your case below everything is likely in the IST, or instance 0. You have a device on 1/0/11 which has won the STP root election process.

 

I could give you a much more complete answer if you provided a diagram, including L2/L3 information.

 

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CCIE 24349, MASE 2011 Networking
Canadian HPN Partner of the Year
Martin Tighe
Occasional Contributor

Re: 5500 STP query

Hi and thanks for the reply, I am a novice with regards to the function of the 5500 so please bare with me.

 

All I am trying to achieve is a resilient failover. I assumed that the alternative port followed the root port which is why I was thinking that the root port should have been port 1 with is where the primary WAN connection is coming into the switch, and port 2 is the backup connection coming into the switch. The two incoming connections are VPLS so I have been told its down to me to create the failover and loop protection. STP has been enabled on the switch, but I was concern that loop protection was not setup nor that I failed to see how to control failover on just two ports......

 

Regards

mnantel
Advisor

Re: 5500 STP query

As VPLS does not handle redundant links, what you must indeed do in this case is to configure monitor link.

Using monitor link, one link will be active while the other will be your backup link. The backup will only start forwarding if the active dies. As this will avoid loops it will work quite fine with redundant VPLS connections!

 

Monitor Link is a function of the 5500. There is ample documentation on the H3C website about this function.

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CCIE 24349, MASE 2011 Networking
Canadian HPN Partner of the Year