[mrtg] Re: Monitor multiple IPs on one physical eth card?

Alex van den Bogaerdt alex at slot.hollandcasino.nl
Tue Oct 16 00:19:35 MEST 2001

jeffrey A. Croft wrote:

> Is it possible to monitor more than one inferface on a single enthernet
> card with MRTG?

The ethernet card *is* the interface.

> I have a system with two interfaces, eth0 and eth0:0, which have different
> IPs, but are on the same ethernet card. I would really like to be able to
> monitor the two IPs seperatley, if possible.

You're not only receiving ip traffic.  The ip traffic that you do
receive is encapsulated in ethernet packets.  The ethernet address
will most likely be the same for both (or even all) ip addresses.
There's more traffic coming into your interface, such as broadcast
traffic, arp requests and replies, icmp traffic etcetera.

You can setup ipchains/iptables/ipfw (whatever is available) and use
it not (only) for firewalling but (also) for accounting.  There are
some examples in the manual pages for that program.  Basically it is
just sending some of the traffic through a counter while other packets
are not passing that counter.

> I just can't figure out how to configure the mrtg.cfg file to do
> this. It's a RedHat 7.0 box. Can anyone help?

Once you're able to generate the numbers, you can use the external
program interface to import them into MRTG.  I suggest that you use
another mailing list or newsgroup if you need more information.

 / alex at slot.hollandcasino.nl                  alex at ergens.op.het.net \
| work                                                         private |
| My employer is capable of speaking therefore I speak only for myself |
| Technical questions sent directly to me will be nuked. Use the list. | 
| http://faq.mrtg.org/                                                 |
| http://rrdtool.eu.org  --> tutorial                                  |

Unsubscribe mailto:mrtg-request at list.ee.ethz.ch?subject=unsubscribe
Archive     http://www.ee.ethz.ch/~slist/mrtg
FAQ         http://faq.mrtg.org    Homepage     http://www.mrtg.org
WebAdmin    http://www.ee.ethz.ch/~slist/lsg2.cgi

More information about the mrtg mailing list