spanning-tree port type edge trunk

[jay_7301]

Hi,

I have been seeing large outages when we see a link flap in our core with RSTP. 

I have noticed under 1 of the links that spanning-tree port type edge trunk is enabled. Should this be used for a switch > switch link or will this cause issues? i thought this should be used for end hosts?

Thanks

[Flavio Miranda]

Hi

This two kind of port config spanning-tree portfast trunk  and spanning-tree port type edge trunk should not be configured between switches, you are right. 

[MHM Cisco World]

This command use in case you connect router to SW

Router is l3 and dont form loop and link to router config as trunk 

So we can safe run portfast in this case.

Never use it in link between SW's

[ammahend]

If the port is not configured as trunk, then this command (spanning-tree port type edge trunk) has no effect, means port is not portfast, it will still do listen Learn forward state and take its time.
However if a port is configured as trunk port then this command (spanning-tree port type edge trunk) will move port immediately to forwarding state. 
So this command can be used where you have trunk port and want to move immediately to forwarding state, ideally between switch you want to go through the STP process so I would not recommend this on a port connecting 2 switches. But other devices which need to be trunk and pass multiple vlan but do not participate in STP like WLC, router on stick, some server, it can be configured. 

[jay_7301]

This has been configured on a VPC port-channel. Would there be any reason to have it on here? and yeah this is facing another switch and is configured as a trunk.

[MHM Cisco World]

vPC of Nexus switch ?

[jay_7301]

correct  - apologies i noticed this might have been posted in the wrong forum.

[MHM Cisco World]

Nsk1 to Nsk2 peer-link 

And from both NSK vPC connect to other sw or server 

This config where ? Between NSK or between NSK and SW and server ?

[jay_7301]

The port-channel  in question  is on a 9k pair and has VPC enabled. This connects to a VSS switch which is configured as mode trunk.

[MHM Cisco World]

Cisco Cisco Catalyst 6503-E Switch White Paper - Page 3 of 8 | Manualsbrain.com

I make review the Cisco white paper for apply this commend between VSS and vPC and there is no any indication 
this additional to what we know that edge (trunk) must config in port connect to host not connect to other SW. 
so there is change that this port make some issue in your network. 
do show spanning tree interface x/x and check 
how many forward status counting