On Wed, 16 Mar 2011 13:58:09 +0100 Joachim Tingvold joachim@tingvold.com wrote:
Any idea what the ifDescr values look like on this device (snmpwalk ifDescr)?
It doesn't have ifName at all, so I guess NAV falls back to use ifDescr?
Correct. If the device doesn't reply to ifName requests, NAV substitutes the ifDescr value as an ifName value.
root@nav:~# snmpwalk -v 2c -c public sw-mgmt-cr2-x02 ifDescr IF-MIB::ifDescr.1 = STRING: FSM726 Management Switch 10/100 Mbps Ethernet Network Interface 1 [...] IF-MIB::ifDescr.24 = STRING: FSM726 Management Switch 10/100 Mbps Ethernet Network Interface 24 IF-MIB::ifDescr.25 = STRING: FSM726 Management Switch 1000 Mbps Ethernet Network Interface 25 IF-MIB::ifDescr.26 = STRING: FSM726 Management Switch 1000 Mbps Ethernet Network Interface 26 IF-MIB::ifDescr.27 = STRING: FSM726 Management Switch CPU Ethernet Network Interface
It would be hard to filter this out on a general basis, I guess, unless one use the ifIndex in conjunction with ifDescr.
We could go about this another way as well. If you look at each individual switch port, NAV has assigned a port number to it, based on the port number found in BRIDGE-MIB (this number is unique across the IP device, even when it has multiple modules).
If a device doesn't reply to ifName, but a bridge port number was found, it could substitute the port number for the ifName value - only falling back to ifDescr if it's not a switch port. What do you think?
Are the port numbers NAV has found for your switch reasonable?