I know how to connect a switch on a router Avaya VSP 7200 by disabling STP with the command :

no spanning-tree mstp force-port-state enable

but how to force port state on a switch Avaya 4950?

Thank you for helping

  • Did any answer help you? If so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you can provide and accept your own answer.
    – Ron Maupin
    Apr 19, 2019 at 14:44
  • No solution We'll probably try a reboot but i don't know when
    – Anti A-H
    May 10, 2019 at 13:40

1 Answer 1


I don't know about the 4900, but on the 5000 (5xxx) line I use the following:

interface FastEthernet ALL
spanning-tree rstp port 21-22 learning disable

(21 is a cablemodem, 22 is the router)

STP will show the ports as Discarding, but they aren't:

troz-5510-1#show spanning-tree rstp port role 21-22
Port     Role       State     STP Status  Oper Status
----  ----------  ----------  ----------  -----------
21    Disabled    Discarding  Disabled    Disabled     
22    Disabled    Discarding  Disabled    Disabled 

troz-5510-1#show interfaces 21-22 
              Status                    Auto                       Flow  
Port Trunk Admin   Oper Link LinkTrap Negotiation Speed    Duplex Control
---- ----- ------- ---- ---- -------- ----------- -------- ------ -------
21         Enable  Up   Up   Enabled  Enabled     1000Mbps Full   Disable 
22         Enable  Up   Up   Enabled  Enabled     1000Mbps Full   Asymm   
  • Thank you for your answers. I need to connect a switch small switch (hp procurve) on my Avaya 4900 because RJ45 outlet are missing in our office. this command above shows that the port state is fowarding. So my issue seems not to come from spanning tree : one switch port seems desactivated but i don't know why. Avaya switch is sending LLDP (first frame) to the device which is connected on but then it doesn't send the BOFL frame which seems to be necessary to establish the connexion. Then the device get no answer to his broadcasts and don't receive the broadcasts of others devices.
    – Anti A-H
    Feb 26, 2019 at 16:19
  • Thank you, that also helped me to be sure I'm not messing things up badly ;) Mar 14, 2022 at 18:39

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.