09-29-2008 09:06 AM - edited 03-03-2019 11:43 PM
We are implimenting etherchannles from the HP virtual connect to our swithces.
HP's suggested config is the following
Interface port-channel 1
swithport trunk encapsulaiton dot1q
switchport trunk allowed vlan 3,4,5
switchport mode trunk
spanning-tree port-fast trunk
!
interface gig0/1
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 3,4,5
switchport mode trunk
spanning-tree portfast trunk
!
Does spanning-tree portfast trunk seem correct?
What would be the benefit of this?
Solved! Go to Solution.
09-29-2008 10:53 AM
Certainly can. A lot of NIC's on servers these days are capable of running 802.1q.
Jon
09-29-2008 10:01 AM
The benefit of this is that even though it is a trunk link it will still act as a portfast access port and not have to wait the full 50 seconds of listening/learning/forwarding.
The command is there specifically for end servers that are connected to the switch via a trunk link.
Jon
09-29-2008 10:08 AM
Hi,
OH ... Long time not see ,
Never set spanning-tree portfast on a trunk ports.. This could result in spanning tree loops , Portfast has to be set on access port where there are host connected not bridges.
HTH
Mohamed
09-29-2008 10:11 AM
Mohamed
Think that's the point. I agree it should never be set on uplinks to switches but it isn't in this case.
Jon
09-29-2008 10:46 AM
I guess I learned that things other than switches can perform "trunking"
09-29-2008 10:53 AM
Certainly can. A lot of NIC's on servers these days are capable of running 802.1q.
Jon
11-04-2010 05:55 AM
Hi there!
Would you recommend to add "BPUDguard" along with porftast on the trunk in order to put the port in error-disabled state in case of BPDU received on the trunk?
Regards,
LLP
11-04-2010 06:52 AM
Basically,BPDU guard runs on ports which are configured with portfast and therefore, connect to end devices.
As these end devices never originate BPDUs, you should indeed configure BPDU guard to prevent spanning-tree loops
caused by miscabling/...
You can read up on BPDU guard at the following link:
http://www.cisco.com/en/US/tech/tk389/tk621/technologies_tech_note09186a008009482f.shtml
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