MRTG -> remote host

Soulstealer · 06-26-2005, 04:48 AM

Hi, guys

I'm running MRTG on my linux box which is router for 2 machines.
The graphs are working fine for my internal and external interfaces.
But now I want separate graphs for the 2 machines behind the router.
How can I do this ?
I tried the following with cfgmaker

Code:

cfgmaker --global 'WorkDir: /var/www/htdocs/mrtg' --global 'Options[_]: bits,growright' public@localhost public@192.168.10.3 public@192.168.10.2 > /store/mrtg.cfg

for public@localhost everything is fine
but for the rest
I got

Code:

--base: Get Device Info on public@192.168.10.3:
Error:
  can't resolve "192.168.10.3" to IP address
 at /usr/local/mrtg-2/bin/../lib/mrtg2/SNMP_util.pm line 426
SNMPWALK Problem for public@192.168.10.3::::::v4only
 at ./cfgmaker line 831
WARNING: Skipping public@192.168.10.3: as no info could be retrieved

can anyone help me ?

thank you

born4linux · 06-26-2005, 09:47 PM

for the two "remote" hosts that you want to graph, you need to have snmp services enabled on both. look for "mrtg snmp howto". if the two boxes are using MS Windows XP, you can insatll the snmp service from the installation CD.

the errors that you have are likely due to snmpd not installed or configured.

Soulstealer · 06-27-2005, 12:56 PM

Thank you

But I don't like this solution...
I realized that iptables can give me the information for the traffic incoming and outgoing from the "remote" hosts.
But I can't understand how exactly to do this
Is something like:
ipt -N download
ipt -N upload
ipt -A FORWARD -j download
ipt -A FORWARD -j upload
ipt -A download -d 192.168.10.2 -j ACCEPT
ipt -A upload -s 192.168.10.2 -j ACCEPT

and then with iptables -L -n -v -x
I can see the bytes and packets
but how to build the target in mrtg.cfg ?

thank you

demian · 06-27-2005, 06:11 PM

Setting up a rule like you said would work. Next thing is to write a script that reads out the second column of the output of iptables -nvxL upload and iptables -nvxL download say every five minutes. The output of the script _must_ consist of exactly four lines: the incoming counter, the outgoing counter, the uptime of the host (this will be hard to come by if you refuse to use snmp but you can just stick the localhost uptime in here and ignore this value) and some_name. Then you can setup a target in mrtg.cfg like so:

Target[some_name]:`/path/to/your/script`
Title[some_name]: blah blah
...

You might want to check out pmacct and consider using that rather than iptables. Also rrdtool handles non-snmp data a lot better than mrtg does and you're not restricted to integer data values or that four line output format. Might also be worth a look.