This menu has settings for configuring basic IPv6 routing functionality on FreshTomato. Settings here affect only routed packets. Generally, IPv6 packets always travel through a FreshTomato router's switch on the LAN, regardless of these settings.
IPv6 Service Type:
IPv6 has several service types, or “modes” it can use. Some service types partly depend on IPv4 services. Others run independently of IPv4. Ask your Internet provider or search the web to find which type your provider uses.
Depending on the service type you select, various fields may appear, prompting you for appropriate settings.
Options include:
Currently, IPv6 is not supported in MultiWAN configurations. Only the first WAN interface can use IPv6.
[Disabled]: IPv6 is disabled by default. IPv6 traffic will still flow if in access point mode.
[DHCPv6 with Prefix Delegation]
This is the most commonly-used Service Type. It provides native IPv6 connectivity to your network. If your ISP gives you a prefix with length smaller than 64, this mode allows you to assign different IPv6 address ranges to bridges 0 (br0) through bridge 3 (br3). Other common prefixes are 56 or 60. The option to assign IPv6 address ranges for bridge 1 (br1) through 3 (br3) is available only if those bridges already exist. Check your settings in the Network menu to learn more.
Example Configuration: German Telekom
German Telekom supports a dual-stack setup of IPv4 and IPv6. For most consumers, it provides a default prefix length of 56. A prefix length of 64 (FreshTomato default) also works. However, with a 64 prefix, it's not possible to assign different IPv6 address ranges to bridges 1 (br1) through 3 (br3).
In this mode, extended options exist. If the prefix is lower than 64, and bridges 1 (br1) through 3 (br3) exist, you can enable subnets for all those bridges, as below.
[Static IPv6]
This mode is similar to Static IP mode in IPv4. With this service type, you enter the IP address and other settings into FreshTomato's menus. Your Internet provider gives you the settings.
[6to4 Anycast Relay]
6to4 is a transitional protocol for migrating from IPv4 to IPv6. 6to4 acts as a transparent transport layer between IPv6 nodes. It allows IPv6 packets to be transmitted over an IPv4 network, such as the Internet, without requiring you to configure explicit tunnels. 6to4 hosts and networks communicate with native IPv6 networks via Special relay servers, known as “6to4 Anycast Relays”.
Note that 6to4 does not support communication between IPv4-only hosts and IPv6-only hosts.
6to4 Anycast Relay performs these functions:
[6in4 Static Tunnel]
6in4 is a static VPN tunneling protocol that allows IPv6 traffic to be transmitted over IPv4-only network infrastructure. It is also known as “proto-41 static”. This is because it has been designated IP protocol 41 and because each endpoint must be explicitly configured.
6in4 Static tunnels IPv6 packets inside IPv4 packets. It's a transitional protocol, to help us get through the transition to all IPv6.
Generally, 6in4 static uses a tunnel broker, a third-party service that provides an encrypted tunnel between you and your destination (ISP). Probably the most common tunnel broker is tunnelbroker.net. If you use a tunnel broker, you must set up a free account on their website before using 6in4 Static.
Example Configuration through Tunnelbroker.net
This example uses tunnelbroker.net to create a standard tunnel.
You should now see the Tunnel Details webpage shown below:
By default, tunnelbroker.net assigns your routed endpoint a routed IPv6 prefix of /64. This lets your endpoint act as the router for your netblock, and use RA/SLAAC or DHCPv6 to assign IP addresses from this allocation to your LAN.
Now, enter the corresponding data from Tunnel Details into FreshTomato:
For more details, see tunnelbroker.net's tutorial for creating tunnels: https://ipv6.he.net/presentations.php
[6rd Relay]
Fix Me
[6rd from DHCPv4 (Option 212)]
Fix Me.
[Other (Manual Configuration) ]
Debug
Checking this sets the Detail level in Logging to the Debug Level. This causes it to log all messages of debug level or higher.
IPv6 DUID Type
Every DHCP client/server has a DHCP Unique Identifier (“DUID”). The DHCP server uses it to identify clients for the selection of configuration parameters.
Options:
You can see the DUID type currently in use in the Overview menu.
Support for DUID Type started in release 2022.4. Fixed DUID types and custom DUIDS are not supported.
Prefix Length
The network prefix is analogous to an IPv4 subnet mask. It represents the network portion (most significant bits) of the address. These leading bits are identical on all hosts on your assigned network.
Other options commonly used iinclude 56 bits. (Default: 64).
Request PD Only
This setting should be enabled for ISPs that require only a Prefix Delegation. This is usually PPPoE-authenticated DSL or fiber connections.
Do not allow PD/Address release
Enabling this prevents DHCP6 clients from sending a release message to the ISP when disconnecting. With this set, the client is more likely to receive the same allocation on subsequent requests.
Support for this option started in release 2022.4.
Add default route ::/0
IPv6 Router Advertisements (through IPv6 ICMP on the WAN interface) will add the default route. As a result, this option is usually required. However, some ISPs, such as Snap (NZ), or Internode (AU) may require you to specify the default route / workaround.
See also Linksysinfo.org: IPv6 and Comcast
Static DNS
FreshTomato users can add/specify DNS server addresses. For example, if you are using DHCPv6 with PD on the ISP German Telekom, DHCP will automatically provide two IPv6 DNS server addresses. However, you can still manually add static DNS addresses if you wish.
Examples:
Accept RA from
This function will cause Tomato to accept IPv6 Router Advertisements.
Options:
When using DHCPv6 with Prefix Delegation, this option is enabled on the WAN interface. It can't be disabled, as it is necessary for that service type.
IPv6 is still new to many people and can be quite different from IPv4. Here are some good sources for learning IPv6 basics:
Network Lessons: Introduction to IPv6
https://networklessons.com/ipv6
Professor Messer: Assigning IPv6 addresses
Professor Messer: Network Plus-IPv6 Addressing