How IPv6 works with Google Wifi

Google Wifi uses a dual-stack implementation, which means that IPv4 traffic and IPv6 traffic may coexist on the same network (both wired and wireless). Google Wifi does not support IPv6 transitional protocols such as 6to4 or 6rd. Additionally, Google Wifi does not support IPv4 over IPv6 or IPv6+.

For IPv6 to work, all of these entities must support it:

  • Your ISP (must also support IPv4; we don’t support IPv6-only connections)
  • Your client devices 
  • The operating system and applications running on your client devices

When IPv6 is enabled on Google Wifi, it uses the DHCPv6 protocol on its WAN port to request an address from your ISP. If the ISP supports the DHCPv6 protocol and has provisioned addresses for routers, then the router will obtain its own IPv6 address. 

If the ISP has not provisioned addresses for routers, then the router will obtain its address using a procedure called StateLess Address AutoConfiguration (SLAAC or “slack”). The router also requests an IPv6 prefix from the ISP, which is used to send the IPv6 router advertisements to the clients on the LAN, allowing them to derive their own addresses.

If the ISP provides a usable prefix, Google Wifi will will start sending IPv6 routing advertisements to clients on the LAN to allow them to pick and validate their own IPv6 addresses using the SLAAC (or “slack”) procedure.

Google Wifi feature behavior with IPv6 

IPv6 reachability testing

To ensure a robust IPv6 connection, Google Wifi periodically runs connectivity tests in the background.  These tests validate the operation of IPv6 connections from your Google Wifi points to the Google infrastructure network. The results of these periodic tests may vary and, depending on the robustness of your ISP’s IPv6 network, your IPv6 connection might become disabled. The tests run automatically and will attempt to restore IPv6 service.

IPv6 port forwarding/port opening

Port forwarding is used with NAT on IPv4 networks. IPv6 networks don’t use NAT for port forwarding. DHCP IP reservations (aka static IP reservations) are not used with IPv6 addresses and aren’t required for IPv4 connections. 

IPv6 on guest network

Google Wifi supports IPv6 on all LAN connections, including wired LAN and private WLAN. Google Wifi also supports guest networking for IPv6, however your ISP must provide a network prefix length that’s less than 64 bits to allow for proper subnet addressing.  If the ISP’s prefix is 64 bits, IPv6 won’t be available on the guest network.