bsnmpd ifSpeed MRTG cfgmaker workaround

catonic

MRTG cfgmaker gave this result for devices such as gif, lo, ovpnc, ovpns:

gif or gif0 :

### The following interface is commented out because:
* has no ifSpeed property

ovpns devices:

### The following interface is commented out because:
### * has no ifSpeed property

ovpnc devices:

### The following interface is commented out because:
### * has no ifSpeed property

No effect for administratively DOWN or operationally DOWN interfaces, or softwareLoopback devices: e.g.:

enc or enc0 :

### * it is administratively DOWN
### * it is operationally DOWN
### * has no ifSpeed property

lo or lo0 :

### * it is a Software Loopback interface
### * has no ifSpeed property

pflog or pflog0 :

### * it is administratively DOWN
### * it is operationally DOWN
### * has no ifSpeed property

pfsync or pfsync0 :

### * it is administratively DOWN
### * it is operationally DOWN
### * has no ifSpeed property

The solution was to change cfgmaker arguments:

/usr/bin/cfgmaker --zero-speed=10000000 -o outfile.cfg community@object

Additionally, --ifdesc=descr changed the Title to start with device or device.vlan where appropriate.

Here is the site that gave me the hint:
https://aacable.wordpress.com/2014/07/07/mrtg-monitoring-with-esxi-hosted-guest-return-interface-is-commented-has-no-ifspeed-property/

https://oss.oetiker.ch/mrtg/doc/cfgmaker.en.html

However, cfgmaker does not have an argument for enabling monitoring of loopback devices, though there is a more complicated method to work around that using something such as '--if-filter=($default_iftype && $if_admin)' with type 24, softwareLoopback as documented at the website above or something like below:

"--if-filter=($default || $if_type==24)"

The positional order is important, all flags need to precede community@router. --if-filter carries a caveat:

--if-filter=f     Test every interface against filter f to decide wether
                   or not to include that interface into the collection.
                   Currently f is being evaluated as a Perl expression
                   and it's truth value is used to reject or accept the
                   interface.
                   (Experimental, under development, might change)

The resulting command line argument contains double quotes:

/usr/bin/cfgmaker --ifdesc=descr --zero-speed=10000000 "--if-filter=($default 
|| $if_type==24)" -o outfile.cfg community@router

If you run into an issue with the shell interpreting the contents, switch to the double quotes to single quotes.

Now lo0 is monitored by MRTG using bsnmpd. To monitor lo0 and everything ethernet:

/usr/bin/cfgmaker --ifdesc=descr --zero-speed=10000000 "--if-filter=($default 
|| $if_type==24 || $if_type==6)" -o outfile.cfg community@router