Q. What variable does InterMapper use to assign names to interfaces in InterMapper Flows? Is this variable ever refreshed?

A. InterMapper populates the interface name in Flows using the "ifAlias (ifName)" variable, if ifAlias is non-empty. Otherwise, it will use the "ifDescr" variable. The variables are refreshed as needed, every three minutes.

Note: For InterMapper Flows to show the names of interfaces instead of the numbers, you need to add the IP address of the Flow Exporter to an InterMapper map using the SNMPv2c probe. InterMapper relies on the SNMP probe to retrieve the interface names and then provides this information to the Flows component.

Flows can only use the numbers reported by the exporter for its interfaces. We get that information on a per-session basis (interface numbers are listed in the NetFlow datagram) and we do not change them. Additionally, Flows only shows the interfaces for which observed sessions have been reported. They won't show up in the exporter list until at least one session has been seen either into or out of that interface.