Charter does not yet offer native IPv6 but they do have IPv6 via 6rd tunnels for testing. It mostly works but I’ve seen some weirdness with various v6 destinations. Thumbnail images breaking on Facebook periodically and things like that.
I have this working on a Cisco 881W running IOS 15.3(2)T with the advsecurity license.
Enable IPv6:
ipv6 unicast-routing
ipv6 cef
Set up a DHCPv6 pool:
ipv6 dhcp pool home-pool
dns-server 2607:F428:1::5353:1
dns-server 2607:F428:2::5353:1
domain-name home.example.com
Tunnel interface:
interface Tunnel0
no ip address
no ip redirects
ipv6 enable
tunnel source FastEthernet4
tunnel mode ipv6ip 6rd
tunnel 6rd prefix 2602:100::/32
tunnel 6rd br 68.114.165.1
Routes & general-prefix:
ipv6 general-prefix DELEGATED_PREFIX 6rd Tunnel0
ipv6 route 2602:100::/32 Tunnel0
ipv6 route ::/0 Tunnel0 2602:100:4472:A501::1
LAN interface:
interface Vlan1
ipv6 address DELEGATED_PREFIX ::1/64
ipv6 nd other-config-flag
ipv6 dhcp server home-pool