Enabling SNMP on my ADSL router

I’ve been playing around with some network monitoring and management tools on my home network and so have been busily enabling Simple Network Management Protocol (SNMP) on a number of my devices, including my elderly Solwise SAR110 ADSL modem/router; however the router’s web interface doesn’t seem to have the ability to configure the SNMP agent.

I asked how to do this on the Solwise forums and the response was to use the command line. Sure enough, I located the Solwise SAR110 Advanced Reference Guide telnetted to the router’s internal interface, logged on, and issued the following commands:

create snmp comm community public ro

(to create a community called public with read only access.)

create snmp host community public ip ipaddress

(to allow a specified IP address to interrogate the device using the public community.)

get snmp host confirmed that the settings were correct.

Enabling traps to inform the SNMP manager of any events was already enabled by default (confirmed using get snmp trap); however the command would have been modify snmp trap enable (or modify snmp trap disable to disable traps).

In order to test the configuration, I ran Noël Danjou’s SNMPTest utility. This confirmed that my router was accessible via SNMP; although I’m not sure if the trap functionality is working as it should be… I certainly didn’t see any evidence of the “System up” trap being sent after resetting the router.

Finally, once I was sure that everything was working as expected, I issued the commit command to save the changes (and re-ran the tests to see if that was why the traps hadn’t worked).

It’s not very likely that anyone reading this blog is using such an ancient device; however the general principle holds true for many consumer devices. If the web interface doesn’t let you do what you want, see if there is command line access, typically via telnet or ssh.

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