vi /etc/ppp/pppoe.conf
CONNECT_TIMEOUT=0
# If you are using rp-pppoe on a physically-inaccessible host, set
# CONNECT_TIMEOUT to 0. This makes SURE that the machine keeps trying
# to connect forever after pppoe-start is called. Otherwise, it will
# give out after CONNECT_TIMEOUT seconds and will not attempt to
# connect again, making it impossible to reach.
PPPOE_TIMEOUT=0
# PPPOE_TIMEOUT should be about 4*LCP_INTERVAL