Cisco 3750 Stack - Port-Channel

Hi,

I am trying to setup two Cisco 3750 Switches which are stacked:

hq-3750-stack1#show switch
Switch/Stack Mac Address : 001d.45b6.bd80
                                           H/W   Current
Switch#  Role   Mac Address     Priority Version  State
----------------------------------------------------------
*1       Master 001d.45b6.bd80     15     0       Ready
 2       Member 0023.05c5.e480     14     0       Ready

I've got my config on and created Port-Channel 1 for a 2Gb Uplink, as follows:

interface GigabitEthernet1/0/4
 description Fibre to core1
 switchport trunk encapsulation dot1q
 switchport trunk allowed vlan 1,5,16-24,32,40,43,44,56,72,82,83,96-98,100,101
 switchport mode trunk
 switchport nonegotiate
 srr-queue bandwidth share 1 30 35 5
 priority-queue out
 mls qos trust cos
 auto qos trust
 channel-group 1 mode active

interface GigabitEthernet2/0/4
 description Fibre to core1
 switchport trunk encapsulation dot1q
 switchport trunk allowed vlan 1,5,16-24,32,40,43,44,56,72,82,83,96-98,100,101
 switchport mode trunk
 switchport nonegotiate
 srr-queue bandwidth share 1 30 35 5
 priority-queue out
 mls qos trust cos
 auto qos trust
 channel-group 1 mode active

interface Port-channel1
 logging event bundle-status

Group  Port-channel  Protocol    Ports
------+-------------+-----------+-----------------------------------------------
1      Po1(SU)         LACP      Gi1/0/4(D)  Gi2/0/4(P)


The config on the core is as follows:

interface Port-channel16
 switchport trunk encapsulation dot1q
 switchport mode trunk
 logging event bundle-status

interface GigabitEthernet1/0/28
 switchport trunk encapsulation dot1q
 switchport mode trunk
 channel-group 16 mode active

interface GigabitEthernet2/0/28
 switchport trunk encapsulation dot1q
 switchport mode trunk
 channel-group 16 mode active


16     Po16(SU)        LACP      Gi1/0/28(D) Gi2/0/28(P)

The core is a 3750G

Port Gi1/0/28(D) comes up then goes down and sometimes goes into a Hot-Standby or just Down.

------------------------

I've been looking at this but keep seeing the port flap:

hq-3750-stack1(config-if)#
Oct 20 20:46:13.056 bst: %LINK-5-CHANGED: Interface GigabitEthernet1/0/4, changed state to administratively down
hq-3750-stack1(config-if)#shut
hq-3750-stack1(config-if)#no shut
hq-3750-stack1(config-if)#
Oct 20 20:46:25.304 bst: %LINK-3-UPDOWN: Interface GigabitEthernet1/0/4, changed state to up
hq-3750-stack1(config-if)#
Oct 20 20:46:26.386 bst: %PM-4-ERR_DISABLE: link-flap error detected on Gi1/0/4, putting Gi1/0/4 in err-disable state
hq-3750-stack1(config-if)#
Oct 20 20:46:28.013 bst: %LINK-3-UPDOWN: Interface GigabitEthernet1/0/4, changed state to down
hq-3750-stack1(config-if)#


Any ideas?
Ian TaylorIT Infrastructure Architect .:|:.:|:.Asked:
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

x
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

JustInCaseCommented:
Looks like that your cable or GBIC is bad.
%PM-4-ERR_DISABLE: link-flap error detected on Gi1/0/4
I guess that if you issue
#sh interface status
Gi1/0/4 status will be err-disabled

You can check error-disable flap values
#show errdisable flap-values

Check the cable and GBIC. Fastest way, if it is possible would be, swap cables with working channel.
If Gi1/0/4 after swap cable (and shut/no shut) is still down - GBIC is bad, if it is up, and other channel is down - cable is bad.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
Ian TaylorIT Infrastructure Architect .:|:.:|:.Author Commented:
Thanks, I'm thinking the same

I will check the cables and gbic
Garry GlendownConsulting and Network/Security SpecialistCommented:
What does "po1" config look like on the stack? err-disable usually rather happens when there is a mismatch in port configuration ...
Is the second port up and does the port channel show the 1G speed?
Choose an Exciting Career in Cybersecurity

Help prevent cyber-threats and provide solutions to safeguard our global digital economy. Earn your MS in Cybersecurity. WGU’s MSCSIA degree program was designed in collaboration with national intelligence organizations and IT industry leaders.

Ian TaylorIT Infrastructure Architect .:|:.:|:.Author Commented:
I re applied the configure last night for all ports which match and gi1/0/4 came up but then went down due to errdisable
Ian TaylorIT Infrastructure Architect .:|:.:|:.Author Commented:
I re applied the configure last night for all ports which match and gi1/0/4 came up but then went down due to errdisable
Garry GlendownConsulting and Network/Security SpecialistCommented:
So g2/0/4 is up and stayed up? What does the first couple lines of "show int po1" and "show int po16" give you? How does "show int g1/0/4" look when it's err-disabled?
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Switches / Hubs

From novice to tech pro — start learning today.