STP Configuration Error

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  • Updated 12 months ago
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Hello Experts,

I'm doing an expasion for a client changing some 1G ports to 10G ports for a inter-switch link.

I only add the vlans on the new port, disable the old 1G port and enable it the new 10G ports. After that the network was having an outage.

Then investigating I look like the customer is using this configuration for STP, for all the vlans, each using his own stpd:

create stpd s35
configure stpd s35 add vlan test ports 1:3 emistp
configure stpd s35 ports link-type broadcast 1:3
enable stpd s35 ports 1:3
configure stpd s35 tag 90
enable stpd s35

Can someone explain me why we have an outage?
Also I will add the same config for the new port, this will be ok?

Greetings

Mario Cruz
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Mario Cruz Torres

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Posted 12 months ago

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Patrick Voss, Alum

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Hello Mario,

If there is a topology change within a STP domain it would cause a brief outage while it re-converges. The amount of time for this outage depends on the size of the network. How long did the network go down for?
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Mario Cruz Torres

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The network never come back, we let the network for 5 min but the outage continue. I need to do a rollback for the old 1G port in order to restore the network.


Grettings
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Prashanth KG, Employee

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HI Mario

From your explanation I understand that the STPD was not enabled for the new 10G ports. If this is the case, we would have had a network with physical loop but no STPD to prevent the loop. This might explain the outage. If this is the case, simply copy the stpd configuration of the old 1G ports to the new ports. 

Hope this helps!
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Mario Cruz Torres

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Hello,

I will applied the same config for the new 10G port, it is need to remove first the old one? Or can I maintain both configuration?

Thanks
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Patrick Voss, Alum

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You can maintain both. If you plan on using this 1g port as an edge port I would recommend removing it before connecting anything else.
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Mario Cruz Torres

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Thanks for the help Patrick, I will do that I let you know my results.