Fibre channel interfaces form Cisco MDS9100 FC switch not showing as expected

[telescopicmop (Greg D)]

CMK version: 2.1 op25
OS version: Ubuntu 22.04

I am monitoring our Cisco MDS9100 FC switches in CheckMK, but noticed that the interfaces are not discovered in the way I was expecting. Rather than showing interfaces, with bitrates etc like it does all other SNMP switches, its showing a “Cisco Digital Optical Monitoring” (DOM) service instead, with some +/-dBm values attributed to them. The even weirder thing is that its showing crit/warn notices on the interfaces that are actually connected.

I say “werid” however its probably more to do with my lack of understanding with how SNMP works on NX-OS. These are the only NX-OS switches we have.

How can I get these to show up as normal switch interfaces instead and report up/down status as well as throughput?

[r.sander (Robert Sander)]

You may want to configure a rule in “Network interface and switch port discovery” as FC ports (56 - fibreChannel) are not of type Ethernet (6 - ethernetCsmacd) and are by default not discovered by the interface check plugin.

You could also read the blog about network monitoring: Network Monitoring with Checkmk: 3 rules to rule them all | Checkmk

You could also enable the HW/SW inventory for that host and look at all the available interfaces and their types first.

[telescopicmop (Greg D)]

Aaaah thank you sir! That sorted it. Just need to filter out the DOM interfaces in another rule now.

Cheers!