How does PPPOE allocate IP address to client?

Question

In a typical private home user to ISP scenario, when PPPOE on a private network router tries to connect to it's ISP, how does PPPOE find and assign a public IP address to the router? Does the ISP's server/router just pull the IP address from a pool of available IP addresses like DHCP?

I thought that PPPOE was simply means of creating a 'secure' channel with authentication. I didnt know it dealt with dishing out IP addresses also. Thanks in advance!

Answer 1

PPPoE Point-to-Point Protocol over Ethernet see ( http://www.cyberciti.biz/tips/pppoe-linux-server-configuration-howto.html )

is basically Radius Validation. (radius stands for Remote Authentication Dial In User Service) PPPoE allows a subscriber accessing the network by using authorization, encryption, compression etc. It can assign from a pool like with DHCP or it can assign a static address to a particular user. The username and password is stored on a validation server at the ISP. When it receives the request it validates the user and can issue several items, including bandwidth limits etc, with the return validation.



To see the similarities to Radius see

http://en.wikipedia.org/wiki/RADIUS

and

http://publib.boulder.ibm.com/infocenter/wsphelp/topic/com.ibm.wesm.doc/wesmpla-radiusattribusedforauthpppoeses.htm



PS it is used to give more control to the ISP for allowed users and privileges than you can do with straight DHCP. It even has an accounting function to track bandwidth and time used.

Answer 2

Normaly if you conect you modem and the source it have it own private address or gateway and when autenticated by your ISP server it asigned a dinamic adress, but if you included a router in the mix so you can conecct more devices to the same source you change the settings to you modem so the PPPOE work in bridge mode, then you run the router setup,follow the instructions then the router became your private autenticated adress from your ISP server, and router asigned the dinamic adresses to the other devices, and all conecct to the same route(trafic cop).

Answer 3

If everything is set right and you do not connect to your router tirelessly, you need to try a physical connection as in an ethernet cable. If this works then it is most likely your wireless modem has gone bad. Without further testing it would be impossible, i would try a physical connection first to eliminate some of the possible issues. if the physical connection works, your router is probably bad depending on the year you purchased, although the linksys router is a good router they typically last 3 years, at least in my experience to eliminate that your router is not bad you need to test another computer to see if it gets wireless internet. If it does then your router is going to be fine and it is probably going to be your wireless card in your computer. Another thing that could be if you do not get internet from wireless but you do on the physical connection is one of 2 things, the dhcp is disabled on the actual router itself when you go into the settings or the tcp/ip connections in your network connections properties portion of your wireless network connections. Ill check this question back later so if any questions just add becouse i can say something and it will not make sence to people and then i can clarify it a little better Ok, i will check back again tommorow and sorry for taking so long to reply, it sounds like your settings in teh network connections are set to a specific dhcp server or something to where the computer will not recive and ip address If your network is not set to need specific ip addresses then you need to set it back to defualt, go to network connections and under this window you need to select on your wireless adapter and click on properties, a window will open that is called the wireless network connecction porperties. Once here depending on your operating system which i beleive it is either xp or vista so i will include how to do this on both. for xp In the networking tab of the wireless network connection properties highlight the internet protocal(tcp/ip) and then click on the button 'properties' it will then open up another windo and click on the buttons 'Obtain an ip address automatically' and 'obtain dns server address automatically' and then ok all the way out for vista In the networking tab of the wireless network connection properties highlight the internet protocal version(you version here)(tcp/ipv(version #)) and then click on the button 'properties' it will then open up another window and click on the buttons 'Obtain an ip address automatically' and 'obtain dns server address automatically' and then ok all the way out if this still does not work then let me know and i will continue to work with you on this problem untill a solution is found