We have a stack of 3750 Switches which logs funny errors in the log. I was able to find similar cases in the forum, but none with a resolution to it. So I try it once again and hope for good input and advise or tips.
The stack contains three switches:
* 1 12 WS-C3750G-12S 12.2(44)SE2 C3750-IPBASEK9-M
2 28 WS-C3750G-24TS 12.2(44)SE2 C3750-IPBASEK9-M
3 28 WS-C3750G-24TS 12.2(44)SE2 C3750-IPBASEK9-M
In the log we receive a lot of Interface down and up messages with a difference of three seconds. See a example further below. What we where able to find out so far:
- Problem only happens on Switch 1 of the stack
- All Interfaces are Fiber SFP GLX-SX Uplinks port to Cisco Access Switches
- Not all Uplinks are affected of this problem
- Reboot of switch member 1 didn't solve the problem, reboot of whole stack we weren't able to do so far
- If we verify the counter part -> User Access Switch of a Intf. which goes down on the core, we see no messages in the log (Down/Up)
- here e example of the config of the uplink port
switchport trunk encapsulation dot1q
switchport trunk native vlan 200
switchport trunk allowed vlan 5,10,30,52,53,90,94,95,190,192,194,195,198,200
switchport trunk allowed vlan add 294,295,900
switchport mode trunk
srr-queue bandwidth share 10 10 60 20
srr-queue bandwidth shape 10 0 0 0
udld port aggressive
mls qos trust cos
auto qos voip trust
spanning-tree guard root
Attached the log filtered with the Down/Up messages.
Has faced such problem on C3750G-12S in a stack.
The problem was in failure of electrolytic capacitors in stabilizers of power supply of controllers.