It seems it's not possible to monitor kvm virtual image network interfaces via SNMP. MRTG's cfgmaker says
### The following interface is commented out because: ### * has no ifSpeed property
and other monitors are consistently reporting that vm's interfaces are exceeding traffic thresholds (even on lo ...). Which is no surprise if the threshold is zero.
I found a hint on some Debian forum that this behaviour is caused by the virtio driver. So I was wondering, is it recommended or are there advantages to configuring one of the emulated drivers instead (ne2k_pci,i82551,i82557b, i82559er,rtl8139,e1000,pcnet)? Or can I "fake it" somehow in the vm's snmpd config?