hello all!

i'm quite new to snmp, but i want to use it to monitor much wrts, it already works fine for eg. traffic data.
the concrete question now is whether i can use snmp to retrieve stuff like the rssi-value.
does anybody have a solution to this?

thanks,
der_flo

*bump*
sorry, it's quite important.

Use the exec module from SNMP coupled with informations coming from wl rssi.

Is there an SNMP package out there that has exec mode compiled in? The package I built doesn't have it.

If you have control of the WRT, you can do anything that storage will allow.  You could write
an SNMP sub-agent to extend the current OIDs.  Just remember that what data you need to retrieve
should be available within 6 seconds.
Some of the SNMP data comes from the /proc file system amoung other places.  I have writen
sub-agents that use a script to get and transmit the data back to the caller.  Of course that was with
apache.  I have not looked at the OpenWRT SNMP packages, so I don't know if you can do that
with them.  But you have the source and can do anything you want to do.

You are talking about using the EXEC/passthru OIDs right? In order to be able to do that you have to have a version of snmp that is compiled with EXEC working. On the net-snmp packages that I built I could never get EXEC working. I see there are now other net-snmp packages out there, do they have exec working?

Hello,

@void Main:
does you mean the possibility to insert some own snmp definitions in the snmpd.conf?
this works fine with the snmp package from the openwrt package tracker

here my configuration:
root@OpenWrt:/etc/snmp# ls
snmp.wlnoise  snmp.wlrate   snmp.wlrssi   snmpd.conf

root@OpenWrt:/etc/snmp# vi snmpd.conf
syslocation Unknown
syscontact root
sysname wrt54g
.
.
.
exec wlrate /etc/snmp/snmp.wlrate
exec wlrssi /etc/snmp/snmp.wlrssi
exec wlnoise /etc/snmp/snmp.wlnoise
....

root@OpenWrt:/etc/snmp# vi snmp.wlrate
#!/bin/sh
/usr/sbin/wl rate | sed -e 's/rate is \(.*\) Mbps/\1/'

here the output of my mib-browser:  (noise is 0 because AP-mode)
.1.3.6.1.4.1.2021.4.101.0    Running out of swap space (0)
.1.3.6.1.4.1.2021.8.1.1.1    1
.1.3.6.1.4.1.2021.8.1.1.2    2
.1.3.6.1.4.1.2021.8.1.1.3    3
.1.3.6.1.4.1.2021.8.1.2.1    wlrate
.1.3.6.1.4.1.2021.8.1.2.2    wlrssi
.1.3.6.1.4.1.2021.8.1.2.3    wlnoise
.1.3.6.1.4.1.2021.8.1.3.1    /etc/snmp/snmp.wlrate
.1.3.6.1.4.1.2021.8.1.3.2    /etc/snmp/snmp.wlrssi
.1.3.6.1.4.1.2021.8.1.3.3    /etc/snmp/snmp.wlnoise
.1.3.6.1.4.1.2021.8.1.100.1    0
.1.3.6.1.4.1.2021.8.1.100.2    0
.1.3.6.1.4.1.2021.8.1.100.3    0
.1.3.6.1.4.1.2021.8.1.101.1    54
.1.3.6.1.4.1.2021.8.1.101.2    24 38
.1.3.6.1.4.1.2021.8.1.101.3    0 (off)
.1.3.6.1.4.1.2021.8.1.102.1    0
.1.3.6.1.4.1.2021.8.1.102.2    0

thanks for your answers!

@tim: is your snmp-package the one from the official buildroot? (http://downloads.openwrt.org/whiterussian/packages/)
if yes, your solution would work great your me!
i think, your post helps me very much, i'll try that as soon as possible.

ciao,
der_flo

Hallo,

@der flo
yes this solution works with the standard snmp package from openwrt-download site.
i test it with snmpd_5.1.2-1_mipsel.ipk

Ahhh, looks like I need to ditch the snmp package I built and get with the program. Thanks!

The stock snmpd package included in White Russian RC3 also works.

It was compiled with the "exec" command that was used in /etc/snmpd.conf

oh yes, it works great!
snmpwalk shows it, i will draw the data as graphs with cacti.

additional question: does anybody know a quite good snmp-tutorial? it seems, that it offers quite nice things, i want to learn it.

thank!
der_flo