I would say no one will find this useful, but I have DSL at home .. I know. The following config is how to add a Cisco router use AT&T DSL. I have done this many times but not in the last two years or so, I had trouble finding good documentation on google for exactly what I needed to do, so I thought I would share.
The main parts of the config needed are creating a dialer interface, setting the authentication and user/pass. Then associating that dialer interface with your Physical Ethernet interface, and lastly configuring the default route.
First lets configure the Dialer Interface
ip address negotiated
ip mtu 1492
ip nat outside
ip tcp adjust-mss 1460
dialer pool 1
ppp authentication chap pap callin optional
ppp chap hostname email@example.com
ppp chap password password
ppp pap sent-username firstname.lastname@example.org password password
Now lets associate that with a real interface:
no ip address
pppoe enable group global
pppoe-client dial-pool-number 1
Next lets set our default route and point it out of the Dialer interface
ip route 0.0.0.0 0.0.0.0 Dialer1
Given we have all our user/pass correct in a minute you should be able to do a “Show IP int br” and see the ip address passed to us by our ATT DSL Modem in bridge mode on the dialer interface.