Hello, Need to send empty value in attribute via coa request for clear any value in current state of attribute and clear attribute itself: # /bin/echo "Context-Name = local, Qos-Policing-Profile-Name='' , Qos-Metering-Profile-Name='' , Framed-IP-Address = yy.yy.yy.yy" | /usr/local/bin/radclient -x -t 3 -c 1 -r 2 -p 4 xx.xx.xx.xx:3799 coa xxxxxx Sending CoA-Request of id 121 to xx.xx.xx.xx port 3799 Context-Name = "dhcp" Qos-Policing-Profile-Name = "" Qos-Metering-Profile-Name = "" Framed-IP-Address = yy.yy.yy.yy rad_recv: CoA-NAK packet from host xx.xx.xx.xx port 3799, id=121, length=32 Error-Cause = Missing-Attribute Event-Timestamp = "Jun 27 2011 10:48:37 MSD" Missing-Attribute is because NAS doesn't receive two attributes Qos-Policing-Profile-Name and Qos-Metering-Profile-Name because radclient doesn't really send it or filtered it, i.e. NAS only received Context-Name and Framed-IP-Address, is this possible to send empty value? -- Alexander Kubatkin