Score:0

net-snmp reporting zero for interface speeds on CentOS 8

ng flag

My monitoring system is using data from SNMP polls to build graphs. This works fine with a few dozen RHEL 6 and 7 hosts, but graphs for all my new CentOS 8 hosts are not working correctly. I've done some checking and the problem is with the ifSpeed MIB returning zero for all interfaces except lo:

$ snmpwalk -v 3 rhel6.foo.internal 1.3.6.1.2.1.2.2.1.5
IF-MIB::ifSpeed.1 10000000
IF-MIB::ifSpeed.2 1000000000
IF-MIB::ifSpeed.3 1000000000

$ snmpwalk -v 3 centos8.foo.internal 1.3.6.1.2.1.2.2.1.5
IF-MIB::ifSpeed.1 10000000
IF-MIB::ifSpeed.2 0
IF-MIB::ifSpeed.3 0

My snmpd.conf on both boxes is identical, the older systems are running net-snmp 5.7.2 versus 5.8.0 on the new ones. Is there any way I can configure the system to properly return an interface speed?

Score:1
za flag

Merely another bug in net-snmp abandonware. Report it. It already has a load of those.

But this has nothing to do with the graphs, ifSpeed is a consultational value (that's probably the reason nobody cares about it). Graphs are using counters, even from another table, that doesn't even have the ifSpeed oid - ifXTable. 32-bit counters from ifTable are buried in the past, where 100 MBit/s interfaces were in massive use.

ng flag
I don't know if you've ever taken a look at the Nagios/Icinga plugin world, but "buried in the past" applies there as well. It's using the `ifSpeed` value to calculate the max for the graph, and doesn't seem to work without it.
drookie avatar
za flag
Nagios/icinga network graphs ? REALLY ? Cacti was used for this these days (and MRTG before it) (and now grafana). You’re confusing things. Icinga/nagios don’t graph anything except availability. Both are purely monitoring software, where “monotoring” is equal for “alerting”. Switch to grafana, really. You're missing an entire topic in your professional resume.
ng flag
All Nagios plugins can output performance data that 3rd party software uses to build graphs. This really isn’t relevant to the question though, which is about net-snmp
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