MRTG IP Traffic for one IP address

Go to "

" and download the "UNIX MRTG Installation Guide." Follow the instructions.

Good luck and have fun.

:>I'd like to see the traffic on the Cisco router of the one IP address using :>the MRTG Linux version program with SNMP.

:Go to "

" and download the :"UNIX MRTG Installation Guide." Follow the instructions.

Vincent, how would do it at all? I looked a few months ago and you can't get at netflow information via SNMP. You can get at ACLs via SNMP, but only for some very specific (and uncommon) platforms.

As I read the posting, the OP isn't looking for information about traffic on an interface, but rather about information for *one* of the IP addresses on the interface.

Perhaps the OP could do something like mirror the traffic for that IP to a loopback interface, have that loopback interface set to drop all traffic, and then read out the stats as interface stats... but that's rather ugly, and somehow I doubt that the MRTG manual would cover that.

What the OP should do is post again with a better description of what they are looking for. If they are looking for NetFlow like information, MRTG is the wrong tool. In a lab environment, if I wanted MRTG to track the traffic to/from a specific IP address, I might try the following:

1 Define two loopback interfaces (X and Y) on the router using arbitrary IPs. Don't use the monitored IP for either loopback. 2 Apply a routing policy to all "normal" interfaces on the router (but not loopback X or Y) to use loopback X as the next hop for all traffic to that specific IP address and to use Loopback Y for all traffic from that specific IP address. 3 Set up MRTG to monitor the two loopbacks (X = traffic to, Y = traffic from) and fix the labels so they make sense.

I would not consider doing this in a production environment because the complexity and obscurity would make it unmaintainable by anyone not privy to the MRTG usage.

In a production environment, if the data had to be displayed in MRTG, I would use a NetFlow tool to collect the data, then pass that data on to MRTG (using MRTG's documented "External Monitoring Script" interface). More work to set up initially, but no time bombs in the router configuration just waiting to go off.