Switching PAgP Errors

[johnmcgrath29]

i am trying to figure out where i am going wrong here i have three switches on layer 3 two layer 2 switches 4 trunk ports in a typical triangle with the layer 3 as my core/distribution switch I have assigned the three vlans I have configure too all three switches and allowed the three vlans on my trunks inter vlan routing was working till i assigned channel-group 1 mode desirable to create two channel ports with PAgP both sides where set to desirable I scratching my head a bit head any ideas?

I have post some of the error messages below?

%EC-5-CANNOT_BUNDLE2: Fa0/21 is not compatible with Po1 and will be suspended (vlan mask is different)

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/22, changed state to down

%EC-5-CANNOT_BUNDLE2: Fa0/22 is not compatible with Po1 and will be suspended (vlan mask is different)

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/23, changed state to down

%EC-5-CANNOT_BUNDLE2: Fa0/23 is not compatible with Po1 and will be suspended (vlan mask is different)

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/24, changed state to down

%LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan10, changed state to down

%LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan20, changed state to down

%LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan30, changed state to down

%EC-5-CANNOT_BUNDLE2: Fa0/24 is not compatible with Po1 and will be suspended (vlan mask is different)

[balaji.bandi]

%EC-5-CANNOT_BUNDLE2: Fa0/21 is not compatible with Po1 and will be suspended (vlan mask is different)

Reason high level -  Mismatch between Portchannel allowed vlan list and Physical Interface VLAN added.

So Compare all the interfaces have same config.

[Reza Sharifi · Accepted solution]

Make sure you have the same number of vlans allowed on the Portchannel on both sides of the connection.

Vlans should be added to the Portchannel and not the physical links.

https://community.cisco.com/t5/switching/whats-this-port-channel-error/m-p/1557572#M155301

HTH

[johnmcgrath29]

fantastic thank you 

[Reza Sharifi]

Glad to help, John.

Good luck!