AT&T Residential Gateway Bypass

Cetificates

Downgrade the AT&T residential gateway's firmware.

Extract the CA, Client, and Private Key certificats.

MikroTik

Bridge

Create a bridge configured with the AT&T residential gateway's MAC address.

/interface/bridge
add name="BR1" mtu=auto actual-mtu=1500 l2mtu=1592 arp=enabled arp-timeout=auto mac-address=xx:xx:xx:xx:xx:xx protocol-mode=none fast-forward=yes igmp-snooping=no auto-mac=yes ageing-time=5m vlan-filtering=yes ether-type=0x8100 pvid=1 frame-types=admit-all ingress-filtering=no dhcp-snooping=no

Add the WAN interface to the bridge.

/interface/bridge/port
add interface=sfp-sfpplus1 bridge=BR1 priority=0x80 path-cost=10 internal-path-cost=10 edge=auto point-to-point=auto learn=auto horizon=none hw=yes auto-isolate=no restricted-role=no restricted-tcn=no pvid=1 frame-types=admit-all ingress-filtering=yes unknown-unicast-flood=yes unknown-multicast-flood=yes broadcast-flood=yes tag-stacking=no bpdu-guard=no trusted=no multicast-router=temporary-query fast-leave=no 

802.1x

Copy the CA, Client, and Private Key certificates to the router.

Configure the 802.1x client.

/interface dot1x client                                                                                                                                                       
add certificate="ATT Client" eap-methods=eap-tls identity=xxxxxxxxxxxx interface=sfp-sfpplus1 

DHCP Client

Configure the DHCP client on the bridge interface.

/ip/dhcp-client
add interface=BR1 add-default-route=yes default-route-distance=1 use-peer-dns=yes use-peer-ntp=yes dhcp-options=hostname,clientid

Hurricane Electric 6to4 Tunnel

Create a Hurricane Electric account.

Log into your account and request a /48 block of IPv6 addresses from https://tunnelbroker.net/

MikroTik

6to4 Tunnel

Configure the 6 to 4 tunnel.

IPv6 Pool

Create an IPv6 pool.

IPv6 Address

Configure an IPv6 prefix on an interface.

AT&T Prefix Delegation

MikroTik

DHCPv6 Client

IPv6 Pool