The radattr plugin for pppd causes all radius attributes returned by the RADIUS server at authentication time to be stored in the file /var/run/radattr.pppN where pppN is the name of the PPP interface. The RADIUS attributes are stored one per line in the format "Attribute-Name Attribute-Value". This format is convenient for use in /etc/ppp/ip-up and /etc/ppp/ip-down scripts.
Note that you must load the radius.so plugin before loading the radattr.so plugin; radattr.so depends on symbols defined in radius.so.