Re: SNMP Returns Negative Value for Network Traffic Stats - toasters

15 Aug 2003


      You're seeing the INTEGER wrap around from positive to negative
from traps.dat
miscNetRcvdKB                  snmp.1.3.6.1.4.1.789.1.2.2.2.0
miscNetSentKB                  snmp.1.3.6.1.4.1.789.1.2.2.3.0
and from the 6.3.1 MIB:
-- miscNetRcvdKB is DEPRECATED; use miscHighNetRcvdBytes
    --  and miscLowNetRcvdBytes
miscNetRcvdKB        OBJECT-TYPE
    SYNTAX            INTEGER
    ACCESS            read-only
    STATUS            mandatory
    DESCRIPTION
            "The total number of KBytes received on all the
             network interfaces, since the last boot."
    ::= { misc 2 }
-- miscNetSentKB is DEPRECATED; use miscHighNetSentBytes
    --  and miscLowNetSentBytes
miscNetSentKB        OBJECT-TYPE
    SYNTAX            INTEGER
    ACCESS            read-only
    STATUS            mandatory
    DESCRIPTION
            "The total number of KBytes transmitted on all the
             network interfaces, since the last boot."
    ::= { misc 3 }
In the old (deprecated) form it was defined as INTEGER which has
a positive and negative range which wraps from positive to negative
on the wrap-around. In the new variables the 64 bit
quantities are split into two (high and low) 32 bit Counters
(Counters are positive, always increasing values)
You can either do math to accommodate the wraparound to negative
(not recommended) or move to the new values and glue the
high and low parts together to get a positive 64bit value.
steve.
former SNMP peon..
...
From: "Ed Alexander" Ed.Alexander@renesas.com
Date: Fri, 15 Aug 2003 11:50:43 -0700
To: toasters@mathworks.com
Subject: SNMP Returns Negative Value for Network Traffic Stats
We use MRTG to monitor filer stats.  All has been working well until
mid-day yesterday. Now, SNMP queries for network traffic stats (Kbytes
sent and received) are returning negative numbers. For example:
[/usr/local/mrtg/filer/bin]# ./snmpget -v 1 yeti public
1.3.6.1.4.1.789.1.2.2.2.0
-79935745
[/usr/local/mrtg/filer/bin]# ./snmpget -v 1 yeti public
1.3.6.1.4.1.789.1.2.2.3.0
-2057424956
What causes this and how do I fix it? The filer is an F820 running
DataOntap 6.3.1. Thanks in advance.
Ed
-- 
Ed Alexander
Senior Systems Administrator
Renesas Technology America
Design Engineering Center - East
ed.alexander at renesas.com