No, MRTG does not cope with negative numbers at all. I have used a workaround, which is to add an appropriate value to the number to make it positive; e.g., if the numbers returned by SNMP are in the range 0 to -99 dBm, add 100. This will produce graphs that look like they should except when no data are returned at all, but the numbers do not correspond with "reality". The true way to cope with this is to use RRDTool.
-- Shane Castle 303-441-3953 -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Craig Metzer Sent: Wednesday, April 18, 2007 09:53 To: [email protected] Subject: [mrtg] Problem with Negative Numbers I'm trying to poll a satellite modem for Rx Signal Level. The modem returns a negative integer ten times the level (ex. -575 indicates the level is -57.5 dBm). I've configured a conversion function so I can log the value returned by snmpget and compare it to the value in the log file. It appears that MRTG is not recognizing the number as negative. It appears it is not recognizing the binary 1 MSD as a negative sign. =========== Config file: ConversionCode: functs.pl Target[my-pub-sat-01-rsl]: .1.3.6.1.4.1.6247.28.1.3.3.4.0&.1.3.6.1.4.1.6247.28.1.3.3.4.0:[EMAIL PROTECTED] pub-sat-01.domain.gov|neg_int ========== Functs.pl: sub neg_int { my $n = shift; open FH, ">> rx_lvl.log"; # my $o = (2^31 - $n) / 10; my $o = $n / 10; print FH localtime(time) . " -> IN: $n\tOUT: $o\n"; close FH; return $o; } =========== Logs: $head my-pub-sat-01-rsl.log 1176910486 2147483590 2147483590 1176910486 0 0 0 0 1176910186 0 0 0 0 1176909900 0 0 0 0 1176909600 0 0 0 0 1176909300 0 0 0 0 1176909000 0 0 0 0 $ cat rx_lvl.log Wed Apr 18 16:29:46 2007 -> IN: -578 OUT: -57.8 Wed Apr 18 16:29:46 2007 -> IN: -578 OUT: -57.8 Wed Apr 18 16:34:46 2007 -> IN: -578 OUT: -57.8 Wed Apr 18 16:34:46 2007 -> IN: -578 OUT: -57.8 ________________________________ Don't quit your job - Take Classes Online and Earn your Degree in 1 year. Start Today! <http://portal.mxlogic.com/redir/?FTK-qekS6kXCQXTvd7ar3dSjo0czOJ8sLzMn6N 0q1wj6cj7ccAygm63C1PUVYTvHTh73zhOO-qem3tPqIpAiV2Hsbvg57OFeDl-syLNWNcSyyy YYrhh7e6zB55YQsTdIK6PiSH6p4QKCy0bhGgfZkQg69j9Cy06uhSszfCy06dGAfzgTfM-u0U SyrhdFTpopvjuvhdOvBRHiPp> _______________________________________________ mrtg mailing list [email protected] https://lists.oetiker.ch/cgi-bin/listinfo/mrtg
