IPv6 RIPE update

IPv6 RIPE update

19th October 2017

On 16/10/2017 RIPE, the European body that coordinates IP Address space, released a BCOP (Best Current Operational Practice) for IPv6 assignment.

The information was published in the document RIPE-690. The full summary can be found here: https://www.ripe.net/publications/docs/ripe-690#4--size-of-end-user-prefix-assignment---48---56-or-something-else-

A BCOP is a best practice document agreed by experts and the wider RIPE community. This BCOP is intended for ISP staff but we have summarised how this should affect the industry and what you should expect from us or other network providers.

The main purpose for the document is to bring consensus and guidance to how ISPs should issue blocks of IPv6 addresses.

Currently, with IPv4, a business connection will be issued with 1 public IP address and NAT is used to translate private IP addresses that need to access resources outside of their network. IPv6 aims to provide both business and residential users with enough public IP addresses that all network devices on their network have their own public IP address; eliminating the need for NAT and providing end-to-end connectivity as originally intended by the Internet founding fathers.

Until now, there has been no official guidance on what IPv6 prefix size should be issued by ISPs to their end users. The smaller the prefix, the more IP addresses and subnets are available to the end user. The latest guidance from RIPE in this document aims to clarify best practice as below:

Business end users: /48 (allows the creation of 65,536 /64 LAN segments)

Residential end users: /56 (allows the creation of 256 /64 LAN segments)

Anything more than a /56 is strongly discouraged by RIPE. This is because there are already enough /48 prefixes so a /56 is already an unneeded reduction in available /64 delegated prefixes for customer LANs. /56 is suggested so ISPs can offer some differentiation between their business and residential products.

As a business to business only supplier, Eclipse Networks and Eclipse Wholesale can supply a /48 IPv6 prefix if requested. This is supplied in a dual stack scenario with IPv4.

It is advised that even if an ISP uses a /127 (i.e. a block of 2 addresses) for the WAN point to point link, a whole /64 should be assigned and just use a /127 from that pool. This is the aid troubleshooting and network planning.

By default, an ISP should offer persistent IP address space in order to reduce logging requirements, make customers more sticky and avoid problems with end-user outages. In some countries non persistent prefixes are required for privacy and legal purposes. For the UK business market, Eclipse will always offer a /48 persistent prefix.

In general, Eclipse are seeing an increase for IPv6 assignments which is a positive step for IP exhaustion, although we do have ample IPv4 addresses via our suppliers to last quite a while. Currently, our managed routers support IPv6 and by request we can assign any managed broadband customers IPv6.