I created the pppoe connection with pppoe-setup.
I dial the connection with pppoe-start
ifconfig does shows the connection ppp0
I checked my ip from whatismyip.com and it showed the ip of modem since my modem also auto dials and to override it, I dial.
Now when I make my ppp0 default route entry, then whatismyip.com shows my pppo connection ip.
I don't want to do this manually.