to be onest, I have no idea where SNMP is used for, but I read in the docs that mrtg is able to work without extra snmp installations. I just want the traffic on eth0 measured.
snmp = simple network management protocol, mrtg uses it to gather network load information.
you need to install snmpd on the boxes you want to monitor; then use cfgmaker to configure mrtg on the box you install it on.
hope this is correct and helps - worked for me :-) pietro.