Creating 127-bit networks in the Global Unicast Address Space - BlueCat Address Manager - 8.3.1

Address Manager Administration Guide

BlueCat Address Manager

Create /127 networks in the Global Unicast Address space to manage point-to-point links between routers.

Using a /127 network provides the least amount of address space: only has two addresses. This allows you to manage the inter-router communication easier, especially in the presence of a large number of point-to-point links. It also has other benefits: always knowing which address the other end uses, and no “ping-pong” problem with older ICMP implementations.

Detailed discussion about the issues and solutions about /127 networks is out of the scope of this documentation, refer to RFC 3627 for more information.

About /127 Networks in Address Manager
  • A /127 network is only intended to be used for point-to-point links between routers.
  • Unlike other IPv6 networks in the Global Unicast Address space with a shorter prefixes such as /64, the Network Router Anycast will not be auto-generated in the /127 networks.
  • You can only create two IPv6 addresses in a /127 network: 0-bit and 1-bit. For example, if you have a 2100:DB8:1000:FFFF::/127 networks, you can only create 2100:DB8:1000:FFFF:0:0:0:0000 and 2100:DB8:1000:FFFF:0:0:0:0001.

To create a /127 network:

  1. Select the IP Space tab. Tabs remember the page you last worked on, so select the tab again to ensure you're on the Configuration information page.
  2. From the configuration drop-down menu, select a configuration.
  3. Click the IPv6 tab. In the IPv6 Blocks section, click the 2003::/3 block.
  4. Under Address Space, click New and select IPv6 Block.
  5. Under Network Information, set the following parameters:
    • Range—enter the /127 network prefix and range: 2100:db8:1000:ffff::/127.
    • Create a Network Range in Sequence Automatically—select this option to have Address Manager automatically create the first possible network in the block. The network prefix and range are calculated automatically and appear in the Range field.
      Note: If you select this option, Address Manager automatically creates a /64 network: 2000:0:0:2::/64. Make sure to change the size of the prefix to /127.
    • Name—enter a name for the network.
  6. Under Change Control, add comments, if required.
  7. Click Add.