Trying to connect c851 router to Internet via AT&T DSL via PPPoE.
If PC connects to internet directly through DSL Modem [i.e. without router], no problem with email or any Windows client.
If PC connects through router, router assigns an IP address to PC, but it will not resolve domain names.
If I ping an external IP address, I receive a response, but if I ping the domain name of the same site (e.g. google.com), it does not respond.
AT&T says router must be configured to obtain DNS server address automatically but I cannot figure how to do that.