Solution “Port is not compatible with aggregators in channel 1 and cannot attach to them”

Once on Cisco Catalyst 6509-E, when I collected an aggregation of three ports, traffic began to go through only two ports and a message appeared in the logs:

Continue reading “Solution “Port is not compatible with aggregators in channel 1 and cannot attach to them””

Configuring link aggregation on the Cisco Catalyst 6500

For the test, I will configure the aggregation on the Cisco Catalyst 6509-E.

Suppose I configured the first port as I need, I registered the necessary VLANs, now with the last commands we add the port to the aggregation channel:

interface GigabitEthernet1/7
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 111,144-190
switchport mode trunk
no cdp enable
lacp rate fast
channel-protocol lacp
channel-group 1 mode active

The second port should be configured in the same way and add the last commands to the aggregation channel as well:

interface GigabitEthernet1/8
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 111,144-190
switchport mode trunk
no cdp enable
lacp rate fast
channel-protocol lacp
channel-group 1 mode active

After the above commands, the Port-channel1 interface was automatically created, use the description command to add a note and enable it:

interface Port-channel1
description GPON OLT link aggregation
no shutdown

The port aggregation configuration is completed, you can connect to them.
I note that it is better to configure aggregation with a pair of links, since a non-pair link is usually less load.
Personally, I prefer not to use channel aggregation, but to use 10Gb/s and 40Gb/s links.

If you need to delete several VLANs, then it is enough to delete them on Port-channel1 (on the ports included in the aggregation, they are deleted automatically):

interface Port-channel1
switchport trunk allowed vlan remove 180-190

An example of viewing various information about aggregation:

show lacp 1 internal
show etherchannel 1 detail
show etherchannel summary
show etherchannel load-balance
show interfaces gi1/7
show interfaces gi1/8
show ip int brief
show cdp neighbor
show lldp neighbor
show interfaces status err-disabled

See also my articles:
Solution “Port is not compatible with aggregators in channel 1 and cannot attach to them”
Configuring link aggregation on Huawei SmartAX MA5600