Freifunk Firmware - Howto install snmpd

This article describes how to install snmpd an a Linksys WRT54 router running FreifunkFirmware (fff) 1.2 or later.

update your packages
Update your lists of available and latest packeges for OpenWRT (whis is the base of fff). To do so use

root@gw2-wrt54g:~# ipkg update


install snmpd with ipkg
To install snmp package and all dependencies also use ipkg as follows:

root@gw2-wrt54g:~# ipkg install snmpd


start snmpd at boot time
After snmpd and all dependencies (libraries etc...) is installed we need to take care snmpd will be started during the boot process. All we need to do is copy (or move) /etc/init.d/snmpd to e.g. /etc/init.d/S52snmpd. The following command does the trick:

root@gw2-wrt54g:~# mv /etc/init.d/snmpd /etc/init.d/S52snmpd


disable the write community
The default setting is to allow snmp access to read and write. The default community string to read is "public" and to write is "private". If you don't want somebody else just reconfigures your WRT you should change the community string to something not easy to guess or bruteforce and never using it (since it is send in cleartext via the network), or even better just disable the community for writing to your WRT. To do so it is neccessary to delete all lines where the word "private" appears in /etc/snmpd/snmpd.conf. you can do that be hand with an editor of your choice or with the following command line:

root@gw2-wrt54g:~# cat /etc/snmpd/snmpd.conf | grep -v private > /etc/snmpd/snmpd.conf


reboot your device
After you did all of the above you should reboot your device to see if everything works. The reboot command makes your WRT reboots. After rebooting your device use ssh to login and check with ps ax | grep snmp if your snmp deamon was started and is running. See sample output below:

root@gw2-wrt54g:~# ps ax | grep snmp
7264 root 1368 S snmpd -Lf /dev/null -p /var/run/snmpd.pid
7266 root 272 S grep snmp
root@gw2-wrt54g:~#


Insead of a reboot you can also just start snmpd with:

root@gw2-wrt54g:~# /etc/init.d/S52snmpd start