No Accounting packets from DD-WRT router running WPA2-Enterprise and RADIUS server in WAN

Question

I am running a TP-LINK WR740N router with DD-WRT. I have successfully set up WPA2-Enterprise which relies on a freeRADIUS v2.2 server in WAN. Authentication goes well. But DD-WRT just sends ACCT request 2 times, when a session starts after successful authentication and when a session ends. But nothing in between. I cannot track how much data are connected devices transferring. I have done tcpdump in port 1813. Nothing captured. I have also checked running freeRADIUS in debug mode. No accounting packets except those two arrives. Is these a limitation of DD-WRT? Or can it be done applying some patch?

Answer 1

DD-WRT almost certainly uses hostapd as its RADIUS client, and hostapd.conf says this:

# Interim accounting update interval
# If this is set (larger than 0) and acct_server is configured, hostapd will
# send interim accounting updates every N seconds. Note: if set, this overrides
# possible Acct-Interim-Interval attribute in Access-Accept message. Thus, this
# value should not be configured in hostapd.conf, if RADIUS server is used to
# control the interim interval.
# This value should not be less 600 (10 minutes) and must not be less than
# 60 (1 minute).
#radius_acct_interim_interval=600

So it sounds like the best thing you can do is configure your FreeRADIUS server to send an appropriate Acct-Interim-Interval attribute in the Access-Accept message, and it should probably not be set to anything less than 600 seconds (10 minutes).

If that's not possible, you should be able to get at DD-WRT's hostpad.conf to override it there.