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PCM+ 2.3x and MSTI mapping

Franck Guenichot
Occasional Advisor

PCM+ 2.3x and MSTI mapping

Hi,
It seems that PCM+ doesn't handle correctly the mapping between MSTI and VLAN in an multi-MSTP instance architecture.

We have 2 MSTI and 2 sets of vlans.
If we look at the vlan map for two vlans mapped to different MST instances, the same links appears to be blocked on the PCM+ VLAN map. Although this is not the case in reality.

Is there something to do, or PCM+ is just not able to map correctly MSTP ?

6 REPLIES
Shadow13
Respected Contributor

Re: PCM+ 2.3x and MSTI mapping

i'm not sure about that but maybe PCM+ show the STP as a whole, like when you issue the command "#show spanning-tree" even when you are enabling MSTP it will give you the redundant link as blocked as STP behaviour, but when issuing "show spanning-tree instance 1" or 2 it will give you the right status for the port for each inst.

I'm not sure i'm just guessing.
abdullah shboull
Frequent Advisor

Re: PCM+ 2.3x and MSTI mapping

The PCM+ 2.3 is show the network topology regarding to the VLAN selection on the topology tap, so if you chose the topology tap on the PCM software and chose the VLAN, itâ ll show you the topology regarding to its VLAN, therefore if you see a blocking link, then itâ s really and you have to review your network design.
Franck Guenichot
Occasional Advisor

Re: PCM+ 2.3x and MSTI mapping

Thanks for your answers, but i think you haven't really understood what i mean:

_ The design is correct, and the blocked links for each instance are the choosen and correct ones.
These informations have been verified with all the STP CLI commands available on the switch

Unfortunately, PCM+ doesn't display correctly the blocked links for each vlan in the vlan topology tabs.

eg:
In reality (viewed with cli commands directly on the switches)

Vlan 200 is mapped to instance 1
Vlan 300 is mapped to instance 2
IST has the same topologie as instance 1 (same root-bridge et backub-root)

link A-B:
_ is blocked for instance 1 (and for IST also)
_ is forwarding for instance 2

If I look at the vlan topology map for vlan 200 : link A-B is displayed in the blocked state (Correct)
And if I look at vlan 300 (in the vlan map)
link A-B is also displayed in blocked state for this vlan (Not Correct)


Shadow13
Respected Contributor

Re: PCM+ 2.3x and MSTI mapping

type show spanning-tree, check the status of the ports and compare it to the PCM+
Franck Guenichot
Occasional Advisor

Re: PCM+ 2.3x and MSTI mapping

:-)
I know that my english is not always good but, I think you missed something.

I've already done this. See my preceding post.

There is differences between PCM+ maps (Incorrect) and real topology (verified by cli commands) on the switches.





Shadow13
Respected Contributor

Re: PCM+ 2.3x and MSTI mapping

i'm talking about show spanning-tree not show spanning-tree instance.
anyway maybe i'm wrong