EtherChannel Configuration

[P Y]

I need some help  with ether-channel configuration between my two switches. I tried to set it  up, but i guess i didn't have the correct configuration because it did not work. 

What would be the proper configuration to connect a 2960x and a 3850 stack together

Switch:    2960X                          3850

interface:   1/0/47          -->           2/0/5

Interface:    1/0/48         -->           1/0/5

I understand that i have to create a port-channel on each switch and then attach that as a channel-group on each of the ports, but when i did that, the interfaces were in a suspended state. I am assuming my configuration inside the port-channel, the interface, or  the switch itself was incorrect. 

Thanks. 

[Robert Falconer]

Can you post the config as you have it?

[P Y]

Here is the relevant config for each of the switches that i had and didnt work.

2960X

interface Port-channel1
 description CHANNEL TO US20SWI254
 switchport mode trunk
 switchport nonegotiate

interface GigabitEthernet1/0/47
 description CONNECTION TO US20SWI254
 switchport mode trunk
 switchport nonegotiate
 srr-queue bandwidth share 10 20 50 20
 priority-queue out
 mls qos trust dscp
 spanning-tree portfast
 channel-group 1 mode desirable

interface GigabitEthernet1/0/48
 description CONNECTION TO US20SWI254
 switchport mode trunk
 switchport nonegotiate
 srr-queue bandwidth share 10 20 50 20
 priority-queue out
 mls qos trust dscp
 channel-group 1 mode desirable

3850

interface Port-channel2
 description CHANNEL TO US20S249
 switchport mode trunk
 switchport nonegotiate
 storm-control broadcast level 10.00
 storm-control multicast level 30.00
 storm-control action trap

interface GigabitEthernet1/0/5
 description CONNECTION TO US20SWI249
 switchport mode trunk
 switchport nonegotiate
 channel-group 2 mode desirable

interface GigabitEthernet2/0/5
 description CONNECTION TO US20SWI249
 switchport mode trunk
 switchport nonegotiate
 channel-group 2 mode desirable

[Robert Falconer]

You should remove the portfast entry from 1/0/47 on the 2960.

Also, try using LACP instead of PAgP. It looks like you're going to different stack members which I think PAgP has an issue with.

[P Y]

yes i missed the portfast statement, which i knew i needed to remove since it was an access port before.....

Yes i am going to two different stack members (so if one fails the communication to the access switch stays up). How do i force LACP?

[Robert Falconer · Accepted solution]

You just use a different mode on the channel-group. The options are active and passive. Active will actively try to negotiate. Passive will respond to requests but will not try to negotiate.

Active/Active and Active/Passive will both work. Passive/Passive will not work.

[P Y]

so....

channel-group # mode active

in the interface configurations will work? I will try this and report  back.

Thanks. 

[s.chaney]

I have a stack of 3 3750. I will remove 2 and replace with 2 3850. The two 3850 will be in a stack. can I join the other remaining 3750 using configs similar to the above?

[P Y]

I was able to figure it out.... 

I had a mismatched configuration between the port-channel and the interface on the 3850 causing the port to go into a suspend state. I made sure that the configuration between the two matched and then shut/no shut the port-channel and the interfaces came up.