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Port security being triggered by firmware upgrades?

Level 1
Level 1

I've started performing firmware upgrades on the PCoIP thin clients that my company uses, but during the restart phase of the upgrade the port security on the switch gets triggered and puts the port into err-disabled state.

Here's an example config from a port that connects to a thin client (all ports connected to thin clients are configured the same):

interface GigabitEthernet0/7
 switchport access vlan 10
 switchport mode access
 switchport port-security
 switchport port-security mac-address sticky
 switchport port-security mac-address stick xxxx.xxxx.xxxx vlan access
 spanning-tree portfast

So yeah, I don't really know why a port would get disabled when the thin client reboots as part of a firmware upgrade. When one is rebooted or turned off normally it does not trigger the port security. Are there any logs I can look at that might tell me? The MAC address doesn't change, which was my first thought when I started looking into this.

All switches are C3560 running IOS 12.2(55)SE5.


1 Accepted Solution

Accepted Solutions

and the default violation action is to errdisable the port. You can change the violation action so that the port doesn't erridsable.

View solution in original post

8 Replies 8

Seb Rupik
VIP Alumni
VIP Alumni

Hi there,

When you encounter one of these incidents can you share the output of:


sh int status err-dis

sh port-security





From show interfaces status err-disabled:

Port      Name           Status       Reason                 Err-disabled Vlans
Gi0/16    PCoIP          err-disabled psecure-violation

From show port-security:

Secure Port  MaxSecureAddr  CurrentAddr  SecurityViolation  Security Action
				(Count)		(Count)		(Count)
Gi0/16		1		1		1		   Shutdown


Any other devices attached to same interface on the switch? 


Try entering "show port-security address" and see if the MAC matches up with the MAC on the device.

Hi there,

Try adding:

switchport port-security maximum 2
! one of the effected switchports. It could be that the PCoIP device shares its ethernet interface with a remote management function like Intel vPro.





and the default violation action is to errdisable the port. You can change the violation action so that the port doesn't erridsable.

I've seen a similar bug on 3750Gs (which are just 3560s with stackwise capability--essentially).

I'm sure it sounds really silly but try this before your next firmware upgrade. Go to the interface for the PCoIP client you're going to upgrade and enter "no switchport port-security" and "switchport port-security" (clear the command and then put it right back). Last time I had a similar bug, where sticky macs weren't being learned correctly and ports were erroring out unpredictably, rebooting the stack did not help, but manually clearing out the port-security command and reissuing it on every interface (with a "range" command once I'd verified it was a fix) resolved the problem forever. I think I was running 12.2(40)SE2 at the time...


Please rate and mark if this is helpful! Thanks!



Level 1
Level 1

In case anyone comes across this, I decided to work around the issue by following cmarva's suggestion of changing each port's violation action from the default "shutdown".

I decided to use the "protect" violation action, and since this will still disallow unauthorized devices from connecting by dropping their packets, it is a suitable solution.


Level 1
Level 1

So I just had this issue upgrading a 3560, and it caused a restriction of a MAC-address of a connected 9200 switch. It was difficult to determine the cause of the issue because the port did not register a violation, the only indication that we had was a server to server connection not working and anything from the 9200 switch would not respond to the server connected to the 3560. We are probably  going to use Zach's advise and try to look at resetting the port security. 

We had upgraded form 12.2.50SE3 to 12.2.55SE12. Although we have to back it down to 12.2.55SE9 because of a bug that does not allow the logging to register the IP address, it comes up as UNKNOWN. 

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