I've previously used STG and MRTG to monitor traffic utilisation on
all of the firewalls/routers we manage. However, recently I've run
into problems with a PIX and also an ASA, both running 7.2 software.
I've configured SNMP and can use GetIF to retrieve SNMP stats. I can
see the device name/description etc. I can see the number of
interfaces, their IP addresses and interface names. I can use the
MBrowser to SNMPwalk and retrieve all sorts of information.
As far as that's concerned, everything looks normal. When I use STG,
I configure the interface number I want to monitor and start polling.
I get responses back - it's not timing out, but my graphs show zero
input and output data. It doesn't matter whether I monitor the inside
or outside interface or whether I do it from inside or outside the
device, I get the same result. I've tried using SNMP v1 and v2c with
the same outcome.
Interestingly, I checked the counters on the OIDs using GetIF MBrowser
and noticed the on both the inOctets and outOctets for both interfaces
there are values, but none of these values are increasing. I've never
experienced an issue like this until now. My relevant SNMP config is
below:
snmp-server host inside 199.0.0.9 community public
snmp-server host outside xxx.xxx.xxx.xxx poll community public version 2c
snmp-server host outside xxx.xxx.xxx.xxx community public
snmp-server host outside xxx.xxx.xxx.xxx community public version 2c
no snmp-server location
no snmp-server contact
snmp-server community public
snmp-server enable traps snmp authentication linkup linkdown coldstart
And, of course, the access-lists allow snmp from the public addresses.
.