We use a Cisco 7200 router for our PPPOE users. As they login cisco creates a virtual interface for the user. we want to trac their internet traffic over this router but when a user logout and login again cisco creates a different cirtual interface for the user so prtg cannot monitor the user and says no such name. In radius we are sending "lcp:interface-config#3=desc USERNAME" to router so there is an always description for user which does not matter in which virtual interface he is. But we could not manage prtg to continue to get the snmp traffic of that user as it gets interface number for traccing user not description. I tried all port identification methods but nothing helped.