Hi, On a Cisco switch, a port is configured as a monitoring port and is part of a monitor session. It is displayed as “down” in CheckMK. How can I still view the performance data for this port? We are still using CEE 2.3.
I’ve already tried using rules for network interfaces and switch ports to ignore or set the status.
Thanks, Andreas
Uh, when a monitoring port cannot be monitored because it is used for the task of monitoring, my brain is close to collapsing. 
I indeed understand the problem… Would it be a too big and too weird task to spin up a small 2.5.0p4 site to just monitor this switch? SNMP allows being queried by different servers, so they should not interfer.
Does this port have a different ifType?
Check with the HW/SW inventory.
Since I was a bit curious about what was going on here, I just gave it a try.
Configured a SPAN session like so
sw01(config)#
monitor session 1 source interface Gi0/8
monitor session 1 destination interface Gi0/3
The result is, the line protocol of the destination port is advertised as down
sh int gi 0/3
GigabitEthernet0/3 is up, line protocol is down (monitoring)
...
Acording to (a bit older) pice of Cisco documentation this is to be expected
(on the destinarion port) All input traffic is discarded and a value of DOWN is advertised as its operational status to all applications running on it.
If I remove the destination for the monitoring session, the interface is comming up again
sw01(config)#no monitor session 1 destination interface Gi0/3 ingress dot1q vlan 1
sw01(config)#do sh int gi 0/3
GigabitEthernet0/3 is up, line protocol is up (connected)
Cheers
Thomas
Hi,
thanks for the feedback.
I’m glad you were able to figure it out. Which version of CheckMK did you use?
The ifType has not changed.
What else can I do to get the performance data?
Checkmk was a 2.4.x, in my opinion the Checkmk version doesn’t matter here.
Remove the monitoring session 
Cheers
Thomas