01-28-2012 11:50 AM - edited 03-07-2019 04:36 AM
Take this configuration on a 6500 with 2 WS-X6716-10-GE modules installed.
interface Port-channel1
description Switch02:Po1
switchport
switchport trunk encapsulation dot1q
switchport mode trunk
switchport nonegotiate
!
interface TenGigabitEthernet1/1
description Switch02:Te1/1
switchport
switchport mode trunk
switchport nonegotiate
channel-group 1 mode on
!
interface TenGigabitEthernet2/1
description Switch02:Te2/1
switchport
switchport mode trunk
switchport nonegotiate
channel-group 1 mode on
shutdown
!
Now I do this:
conf t
int Te2/1
no shut
This error message is generated:
%EC-SP-5-CANNOT_BUNDLE2: Te2/1 is not compatible with Te1/1 and will
be suspended (trunk mode of Te2/1 is trunk, Te1/1 is dynamic)
The million dollar question - Why would it see Te1/1 as being in dynamic trunking mode?
01-28-2012 02:05 PM
Shutdown the port channel by shutting down the port channel SVI . Then try to bring it up , with a no shut on the port channel SVI , this will bring both ports up at the same time. Sometimes they do not like having a single port in the channel being brought up by itself. Also make sure the other end matches exactly seeing you are forcing the port channel to an on state.
01-28-2012 09:01 PM
glen.grant wrote:
Shutdown the port channel by shutting down the port channel SVI . Then try to bring it up , with a no shut on the port channel SVI , this will bring both ports up at the same time. Sometimes they do not like having a single port in the channel being brought up by itself. Also make sure the other end matches exactly seeing you are forcing the port channel to an on state.
I agree this may work, but it doesn't really address the problem. If both the logical and physical interfaces have 'switchport nonegotiate' configured, why would the switch see it in Dynamic Trunking mode?
One thing I did try was removing 'switchport nonegotiate' from Te2/1. Then I got this:
%EC-SP-5-CANNOT_BUNDLE2: Te2/1 is not compatible with Te1/1 and will be suspended (dtp nonegotiate of Te2/1 is 0, Te1/1 id 1)
It's now saying DTP is disabled for Te1/1. In other words, it is NOT in dynamic trunking mode. Since that directly contradicts the earlier message, my conclusion is this is a software bug.
12-30-2016 09:55 AM
I noticed a similar log when I was completing a configuration.
%EC-5-CANNOT_BUNDLE2: Gi1/0/11 is not compatible with Po1 and will be suspended (vlan mask is different)
I had mistyped the allowed vlan on an interface. This caused the allowed VLAN list to be different on the port-channel that I created and the interface.
The port came up after I corrected this issue. I just thought I would share this for anyone seeing a similar issue.
01-28-2012 02:06 PM
Because in both of your physcial interface, you don't have the command "switchport trunk encapsulation dot1q" while this line exist in Po 1.
01-28-2012 02:14 PM
I am surprised the router will let you configure the mode as trunk without specifying the encapsulation first.
Switch(config-if)#switchport
Switch(config-if)#switchport mode trunk
Command rejected: An interface whose trunk encapsulation is "Auto" can not be configured to "trunk" mode.
Switch(config-if)#switchport trunk encapsulation dot1q
Switch(config-if)#switchport mode trunk
Switch(config-if)#
01-28-2012 09:07 PM
Reza Sharifi wrote:
I am surprised the router will let you configure the mode as trunk without specifying the encapsulation first.
The 6500s and 4900s do not seem to support 'switchport trunk encapsulation' on physical interfaces at all. My assumption is since these platforms only support 802.1Q, Cisco just removed the command?
Odd that they kept it there for logical interfaces. Kind of confusing.
01-28-2012 09:30 PM
The 'show int switchport' command also agrees that the physical port is NOT in dynamic trunking mode:
Switch01#sh int te1/1 switchport
Name: Te1/1
Switchport: Enabled
Administrative Mode: trunk
Operational Mode: trunk (member of bundle Po1)
Administrative Trunking Encapsulation: dot1q
Operational Trunking Encapsulation: dot1q
Negotiation of Trunking: Off
Access Mode VLAN: 1 (default)
Trunking Native Mode VLAN: 1 (default)
Administrative Native VLAN tagging: enabled
Operational Native VLAN tagging: disabled
Voice VLAN: none
Administrative private-vlan host-association: none
Administrative private-vlan mapping: none
Operational private-vlan: none
Trunking VLANs Enabled: ALL
Pruning VLANs Enabled: 2-1001
Capture Mode Disabled
Capture VLANs Allowed: ALL
Unknown unicast blocked: disabled
Unknown multicast blocked: disabled
01-28-2012 09:48 PM
Ok ... I think I remember this.
Firstly, you need to delete the port-channel interface (no interface po1). Next, you need to remove the channel-group from both Ten 1/1 and Ten 1/2.
After this is done, do you put the "channel-group 1 mode on" back in.
conf t
no int po 1
int r ten 1/1 - 2
no channel-group 1 mode on
channel-group 1 mode on
end
Try this and let us know.
01-29-2012 08:44 AM
Yes, I think blowing away the Channel and re-creating it would work. However I'm trying to find a procedure that has as little downtime as possible.
Alternatively I think this would work:
1) Create a channel Po2
2) Migrate Te2/2 to it
3) Shutdown Te1/1, then migrate it to the new channel
3) Delete Po1
Since it's a Layer 2 channel and both switches run RSTP, the only downtime would be shutting the old channel and RSTP flipping root ports, which would be under 1 second.
02-07-2012 02:07 PM
Well, at least I'm not alone - http://www.cciezone.com/?p=167
05-07-2014 01:02 PM
Hey........thanks for this I just had this same problem on some old gear....your statement above got my port-channel going.
06-07-2017 01:01 AM
Had the same issue and worked for me, too. Thanks!
01-28-2018 05:50 AM
Dear Friend, how did it work for you?
I'm having the same issue with my VSL plz help, my port-channel is also not coming up.
BR
03-15-2012 11:42 AM
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide