The older versions of the 200 series firmware did not have SNMP. However if you upgrade to the latest version and log into the GUI you can go into Security >> TCP/UDP Services and enable SNMP. Then go down to the SNMP section to configure according to your MRTG settings.
MRTG itself is a program that resides on a computer or server somewhere, which then sends SNMP requests to the switch, which responds with various bits of information.
The SNMP info available from the 200 series is not as extensive as something you would get from a Catalyst switch, but you can at the least get things like port status, speed, duplex, packet counts, etc.
Hope that helps,
Christopher Ebert - Advanced Network Support Engineer
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