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MRTG and Linux FC4 and Linksys WRT54G (running DDWRT)

Medium Priority
Last Modified: 2010-05-18
I would like to be able to generate statistics/graphs on my FIOS internet connection.

I have a Linux FC4 server, with Linksys WRT54G (v4) running DDWRT.  I have enabled SNMP through DDWRT, but I could not find any documentation that states that MRTG supports the WRT54G?

Could anyone please provide a yes/no on this question, as well as any specific configuration issues I may run into?

If there are easier tools out there than MRTG I would be very open to suggestions.

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have a look at cacti http://www.cacti.net/ .

Quick easy setup.

As far as the snmp stats, as long as you have the community names/authentication for snmp setup, network statistics are usually a very basic and standard part of snmp enabled devices.

Again I have to emphasize the simplicity of Cacti.  No manual scripting.  Once you have the database setup, it is all web interface for configuration past that point.  If you can seutp MRTG, you can definitely setup Cacti.  I like K/Ubuntu.  The repositories have Cacti already there.  You install cacti fro the repositories...  Install the database, and you're good to go!

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Wow, great suggestion!  Cacti looks like a breeze to setup compared to MRTG.

I am assuming I have all the SNMP config options I need in DDWRT.  When I enable SNMP I get the following options:

Location: Unknown
Contact: Root
Name: dd-wrt
RO Community: public
RW Community: private

So will I just be able to configure Cacti using these settings?  Sounds easy enough.  I'll leave this question open in case I have any issues.  Thanks so much.
sounds good so far...  Do yourself a favor, if you have anyone else connecting to your network, change the public/private community names so people can't mess with your settings.  SNMP has enough security problems already, not to discourage you from using it, but it is always worth taking the easy steps at a minimum to secure devices.

I'm not familiar with DDWRT, but if it didn't have the interface statistics, it would be like selling a car without wheels, or a house without a roof.

Best of luck!  We use cacti for our customers who don't want to pay for higher end monitoring and trending solutions.  It has worked great this far.  It takes a few minutes to figure out how the configuration interface is layed out, but once you get it, it is much quicker and easier that MRTG, and there seems to be a fairley active community and support forum out there for it.

Best regards,


I will definitely update the SNMP settings, even though I am the only one on the network (home network) but it can't hurt to make it a tad more secure.

I'm working through the RRDtool (component of Cacti) installation and having to tip-toe through freetype2 installation issues.

I'll let you know how everything goes.

One thing to mention just for clarity...  To poll interface statistics with cacti or such, it is a standard MIB that snmp polls.  So it won't be a proprietary request/command and what not.  The snmp command that you would use to poll interface statistics on a firewall, router, switch, jet direct card will be the same for all the devices.   With snmp there are portions of the protocol setup to support proprietary functions for vendor specific needs.  But since the request for interface statistics is a standard, cacti should be able to pull stats from your router just as easy as a cisco 2600 or such.

Sounds like you are making good progress,


I got cacti up and running successfully ("yum install rrdtool" solved all of my freetype2 installation issues :) ).

And I created a new device for my WRT54G linksys router, and I set up a standard SNMP - Generic OID Template, but it appears that none of the traffic that is going through my router shows up on any of the graphs after I add the device to the graph tree.

I have a "localhost" graph set up for my linux server and that is graphing perfectly, so I know it is able to capture info successfully.

I also know it is able to communicate with the Linksys router because it gives its status as "up" and it shows the SNMP name and location that I have only configured on the router itself.

Should I open up a new question for this? or do you have any quick ideas that might solve my problem?

Make sure that SNMP - Interface Statistics is an associated data query.  Delete the graphs currently associated with the device.

Next when on the device page go to the top right of the page, and select "create graphs for this host".

On the bottom right select graph type "in/out bits".  Next just above where you selected the graph type you should be able to see the data query "snmp interface statistics" and select the interfaces you want to graph.  If that doesn't work, you may need help from someone with a deeper understanding of the rrdtool, or cacti that I have.

When I set the graphs up the first time, several of them didn't work.  But going through the steps I just listed solved my problem.

Hope that is helpful.



That was a great help, thanks!  I only had one interface enabled, and it was 'eth1/6' which displayed nothing.  I enabled all of the interfaces to see what showed data, and the following interfaces show data:


Any ideas on which is the overall traffic pattern for the router that I should be using?  Not sure what the diff is between br, eth, and vlan.


Ah, according to this document (http://wiki.openwrt.org/OpenWrtDocs/Configuration):

vlan0 = LAN
vlan1 = WAN
eth1 = WIFI
br0 = LAN and WIFI bridged together

I'm guessing that is correct.

Anywho, thanks a lot for your help, I wish I could give you more than 500 pts :)


here's a more detailed description of the ports on a Linksys WRT54G, in case anyone else needs it:

eth0 - The physical ethernet interface that connects to the 6th ethernet port of the switch
eth1 - the onboard 802.11G wireless card
vlan0 - The 'LAN' ports vlan
vlan1 - the 'WAN' port vlan
br0 - the bridge device that ties vlan0 and eth1 together.

So, I had it graphing eth1 for 12 hours when I didn't have my laptop on so no wireless activity was preset, thus the problem.
Glad that worked!  Thanks for the points!
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