Update below on IPV6 Address Space allocation - 10th October 2018.

Hi All,

With the introduction of BYOD (some customers choosing not to use a 2degrees supplied Fritzbox), we've had a bunch of queries about ipv6, how we provision it, what technologies we use etc. In order to assist you with troubleshooting any other equipment you may use, the team (Thanks Aaron) have pulled together the following information.

2degrees uses Juniper equipment to terminate subscribers, checkout the following links for more information on the architecture used and the implementation overview - Basic Architecture of a Subscriber Access Dual-Stack Network and Overview of Using DHCPv6 Prefix Delegation.

2degrees uses DHCPv6 Prefix Delegation to assign IPv6 prefixes to customer CPE, the only requirement this puts on the CPE is identification and choosing a prefix for delegation. 

DHCPv6 prefix delegation process

 

1. The BNG provides IPv6 prefixes available for delegation.  In the case of dynamic customers this is provided by a local address-assignment pool, and for static IPv6 customers the BNG is informed of the /56 prefix to use via our RADIUS server.  Even though it’s a static assignment the BNG will still delegate the prefix to the CPE using DHCPv6.
2. The CPE requests one or more prefixes from the delegating router.  The standard is a /64 allocation per LAN segment.
3. The BNG chooses the prefixes for delegation, and responds to the CPE.
4. The CPE is then responsible for the delegated prefixes.

CPE WAN link

Below are the methods we support:

 

1. Link-local IPv6 address – The link-local address is provisioned by the appending the interface identifier negotiated by IPv6CP with the IPv6 link-local prefix (fe80::/10).
2. DHCPv6 prefix delegation – The CPE can use the prefix it receives from the BNG to assign an IPv6 address to the interface between the CPE and BNG.  A Fritzbox modem uses this method by default.

Fritz configuration example (in lab environment)

• This is the default setup and will establish a native IPv6 connection, the below configuration would be more specific

• Here you can see the IPv6 address assigned to the CPE-BNG interface and the prefix that was delegated.
• The Fritz in its default setup will assign the first available /64 to the LAN segment.
• For our dynamic subscribers we allocate a /48 or /56 address space depending on the version of code they are running (due to our currently upgrades in progress), for static customers we allocate a /56 address space. Upgrades are planned to be completed in the first week of November 2018 which will see us standardise on /56 for all subscribers.

Nick.