Port-Channel - Trunk - Spanning-Tree - Server 802.1q

[pr0t]

Greetings,

I'm trying to find more information on how to combine spanning-tree and port-channel (which is also a trunk port).

The connection is between a server (2x10G NICs) with NIC Teaming configured for a few particular VLANs. Then we have the switch with two ports (10G) bundled into a port-channel, LACP, configured as trunk. According to what I've found so far, spanning-tree portfast doesn't work against trunk port - so should it be spanning-tree portfast trunk in this case?

If it was a simple port-channel connected to a single VLAN - should I use spanning-tree portfast (only)? 

Regards.

[ngkin2010]

Hi,

spanning-tree portfast trunk should be used on trunk link regardless the number allowed VLAN.

If the switchport is a access port (e.g. configured with switchport mode access), then you should use spanning-tree portfast.

[pr0t · Accepted solution]

Hi gkin2010,

Thank you, for such a quick response. So I should go with spanning-tree portfast trunk - sounds good.

There's one more thing that's bothering me regarding this configuration:

1. When I configure spanning-tree for my port-channel - will the configuration go further down and be applied to each individual (physical) port?

2. Or maybe I should manually configure spanning-tree for physical port,1 then 2 and then do the same with my port-channel?

Regards

[ngkin2010 · Accepted solution]

Hi,

Apply to port-channel interface is fine. But according to my experience, some commands (like spanning-tree cost) will not apply to LACP members automatically. 

So, you could use keyword range to apply the command to logical interface + physical interface at a time.

interface range Po1,Gi1/0/1,Gi2/0/1
  spanning-tree portfast trunk