error 737: loopback was detected on dialin

[Efren Bravo]

Hi,

After configuring mgetty, I tried to call from a winXP client box but it
raise an error after trying to authenticate itself: error:737 loopback was
detected.

My /etc/ppp/ppp.conf has:
default:
 set speed 38400

pap:
 enable pap
 set ifaddr 7.96.160.11 7.96.160.12
 enable proxy
 enable passwdauth

 allow users efrenba

 accept dns
 set dns 7.96.160.5

 I've followed the 21.2.1.3.10 freebsd handbook instructions.
 What can be happening?

 Thanks....