I just recently activated my modem (arris surfboard 6700-ac) and am having the same issue as seen in the link below and others are having where I am getting assigned an ipv6 ip but not an ipv4. Customer service on the phone has been running me in circles so I'm hoping someone here can point me in the right direction.
Hi, Denny671 - Let me check your modem provisioning. Please send me your full name, the account holder's name as it listed on the billing statement, a phone or an account number in a private message. Thank you!