if we have some connection like :pppoe,lan,dialup etc.connection can be up,but remmeber we need to use that chosen connection Gateway to connected Net!
route del default : for delete default gateway
route add default gw XXX.XXX.XXX.XXX
route -n view connections and their Gateway
cat /etc/resolve.conf :view DNS
if you connect PPPOE and you have Bridg connection so u need to use this Comand line
Route add default dev ppp0