[mrtg] ifNumbers Not Working for Low Speed Interfaces When MRTG Parallelized

[Gordon, Bruce]

Hello,

We've been using MRTG on Linux for years.  Since one of our sysadmins updated our MRTG to 2.16.2 we have noticed that some of our graphs are breaking.

We manually roll our own configs which we then run from a script that reads in a file that contains subdirectory names and the subdirectories contains the config file.  The script runs mrtg against that cfg file in the background.  A "wait" command at the end of the shell script.  In this manner we are able to parallelize the execution of the configs (one per device) so one unresponsive device (some can have hundreds of interfaces) does not wrap the monitoring interval.

I know it's old-school and RRD would solve all our problems but ... It works.  Or it did.

Now the majority of the devices polled have SNMP ver2 counters so we tend to put them at the head of the file with a "Target[$]: :<community>@<device>:::::2~" string then reset the Target string to "Target[$]: :<community>@<device>~" before the sections dealing with i/fs with non v2 counters.

What we now get is:

2010-06-08 15:13:27: WARNING: Can not determine ifNumber for <community>@<device>   ref: 'Name'     key: 'Et1/1'
2010-06-08 15:13:27: WARNING: Can not determine ifNumber for <community>@<device>   ref: 'Ip'       key: '192.168.1.1
2010-06-08 15:13:28: ERROR: Target[et1_1][_IN_] ' $target->[5]{$mode} ' did not eval into defined data
2010-06-08 15:13:28: ERROR: Target[et1_1][_OUT_] ' $target->[5]{$mode} ' did not eval into defined data
2010-06-08 15:13:28: ERROR: Target[tu1][_IN_] ' $target->[6]{$mode} ' did not eval into defined data
2010-06-08 15:13:28: ERROR: Target[tu1][_OUT_] ' $target->[6]{$mode} ' did not eval into defined data

When running the script.

The weird thing is when we run mrtg directly against the target (i.e. "mrtg mrtg.cfg") we get no error - i.e. it determines the ifNumber

Any ideas? (Other than spanking the sysadmin)

Regards,

Bruce