SNMP Traffic for specific IP
is it possible not only to visualize the traffic per interface via SNMP, but also the traffic (in and outgoing) of a specific IP via SNMP?
Similar to Status: Traffic Graph, but only via SNMP?
No, you can't get that data from SNMP.
You might be interested in setting up bandwidthd, or netflow. Netflow would let you export the traffic data to another server where it can be graphed.