![which address is used in the address field of a ppp frame which address is used in the address field of a ppp frame](https://www.ictshore.com/wp-content/uploads/2017/06/1061-02-PPP_Frame.png)
Of course if one end does not support a feature or offers an alternative, the CONFREJ and CONFNAK messages. This means both send out a CONFREQ and both must send a CONFACK agreeing to the requested parameters. In order for PPP to finish LCP, both ends must agree on the way the intend to run PPP on the link. Static one IP address (not available for PPPoE!).
![which address is used in the address field of a ppp frame which address is used in the address field of a ppp frame](https://i.imgur.com/1KfXTvZ.png)
![which address is used in the address field of a ppp frame which address is used in the address field of a ppp frame](http://www2.ic.uff.br/~michael/kr1999/5-datalink/ppp2.gif)
The other main reason is dynamic IP addressing. This is one of the main reasons why you’d use PPP to begin with. PPP is a standards based protocol that offers authentication at L2.