mrtg help

[David Bandel]

On Sun, 14 Nov 2004 18:34:00 -0800, Net Llama! <netllama at linux-sxs.org> wrote:
> Good evening,
> I'm trying to get mrtg working, and i'm stuck on getting snmpd working.
>     Each time I try to run mrtg, i'm seeing this error:
> SNMP Error:
> no response received
> 
> In snmpd.conf, i've got:
> com2sec readonly localhost public
> 
> What am i missing?

not sure, but try this:
first, run snmpwalk from the localhost:
snmpwalk -v 2c -c public localhost
then try the same thing from the same host, but use the hostname that
refers to your ethernet card.
Then go to your mrtg system and try to run snmpwalk against the remote host.
If the first two work, but the last one doesn't, make sure that your
mrtg host is requesting the data from the near ethernet card and not
the far card.
Explanation:
Most routers have more than one ethernet (or other) interface.  The
mrtg host will normally be pointed to the hostname of the router, but
that may resolve to an interface IP that goes _through_ the router
rather than hitting the nearest (via routing) interface.
Because SNMP uses UDP, if you request data from an interface that is
logically on the other side of the router, you'll get your answer back
from the near side interface and snmpwalk isn't expecting that, so
discards that data (or netfilter blocks it as not RELATED).

If the first two snmpwalks don't work on the localhost, keep looking
at your snmpd.conf security settings.

HTH,

David A. Bandel
-- 
Focus on the dream, not the competition.
            - Nemesis Air Racing Team motto