06-20-2023 02:26 PM
I am trying to install a Cisco Catalyst 24 port 3750-X series switch and need to trunk port from a Cisco Catalyst 3850. I'm using gi1/0/21 on both switches for consistency. I think I have the correct commands configured but I want to make sure before hooking them up.
3850: config t > interface gi1/0/21 > switchport mode trunk > end
3750: config t > interface gi1/0/21 > switchport trunk encapsulation dot1q > switchport mode trunk > end
Thank you.
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06-22-2023 08:45 AM
According to cisco doc. Above there is no problem if some SW use r-pvst and other use pvst.
Check doc. Above (mixed mode)
06-20-2023 02:33 PM
It easy yes the command is correct, but interconnect two SW you need to check first the STP mode in both SW.
Otherwise loop can happen or vlan is BLK.
06-21-2023 05:58 AM - edited 06-21-2023 05:59 AM
Both switches have spanning-tree portfast in the configuration.
06-21-2023 06:28 AM
STP mode
i.e.
MST
PVST
R-PVST
RSTP
these mode
06-21-2023 06:52 AM
3850: rapid-pvst mode
3750: pvst mode
06-22-2023 08:45 AM
According to cisco doc. Above there is no problem if some SW use r-pvst and other use pvst.
Check doc. Above (mixed mode)
06-22-2023 10:22 AM
I got everything to work. Thank you for your assistance.
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