I was able to successfully connect on Mandrake with Verizon DSL after a couple of hours of research, so i will tell what i did finally
Step 1
1. Install the rp-pppoe package from the mandrake cd. I hope u know how to do this.
2. Then follow the steps given at this link
http://www.roaringpenguin.com/pppoe/how-to-connect.txt
note: i entered "server" when it asked for DNS server.
Hope this helps.