Graphing Peering

druid at druid at
Thu Jan 20 14:45:44 UTC 2005

On Wed, 2005-01-19 at 22:41, andrew matthews wrote:
> Anyone have any suggestions on graphing peering on a cisco router? I'm
> using mrtg and i did mac address accounting but the numbers are off.

off in what sense? We use mac-accounting, snmp nad mrtg to graph per
peer utilization. The following script is helpful

I reworked it to spit out the AS number instead of the ip address. The
issue you then have is that multiple sessions with one As number all
show as the same target. Which MRTG does not like. You can fix that as
well of course in the script. And it does not "autoscan", which means
that if people change their mac-address, you lose the data, until you
rerun the script.

Another problem you might run into is counter wrapping. When polling
every 5 minutes, some counters may wrap. (there is no 64 bit counter for
the mac-address accounting). So you have to run it in short timeframes,
causing more cpu utilization.

But all in all, mac-accounting and Netflow source-as give you a very
good overview of your network flows.


More information about the NANOG mailing list