Can't access Internet?

[Tim Tyler]

FreeRadius experts,
   We are trying to run FreeRadius on a RedHat AS 2.1 system.  We use 
an external password file for authentication defined in the unix 
system (password = filename) section of radius.conf.  This seems to 
work fine.  Modem users can authenticate to our old 3com Total 
Control modem pool, but users can not access the Internet.  They can 
access all local domain servers on campus, but they can't get off 
campus.  This really should not be a firewall  issue as the same ip 
addresses are still associated with the modem pool.
   Note: if we go back to our old Lucent Technology radius server 
running on AIX, everybody is fine and can access the Internet again.
   I am trying to find out what might cause a modem pool to only work 
locally (access servers on our campus) after switching to FreeRadius 
particularly since it seems that the authentication part is 
working?  I know that the 3com Total Control modem pool is rather old 
but I don't know why it would behave differently from one radius 
server to another as long as authentication works.
   I read in one of the FreeRadius archives that some users have 
experienced a similar problem of either very slow or won't work at 
all for some customers accessing the Internet via Freeradius 
authentication until they modified the MTU setting.  This is curious 
to me.  Is there a place in FreeRadius that I might change the mtu 
setting given that I am using an external unix password crypt file 
for all authentication?  If so, what mtu setting might be recommended?
   Is there another possible explanation that might relate to Freeradius?
any thoughts are much appreciated?



Tim Tyler
Network Engineer - Beloit College
tyler at beloit.edu