Address Planning for Infrastructure
Imagine that we are organizing the addresses for the network of an ISP. We may need to consider our requirements for:
- Loopback identifiers
- Links between the two points
- Server internal networks (for NMS and other NOC servers)
- networks of external servers (for mail and DNS services, for example)
Let’s designate a /40 for backbone infrastructure for the purposes of this demonstration. All infrastructure assignments made from this block will be routed using our preferred IGP.
- Loopbacks: One /48 can be set aside for the assignment of loopback (/128) addresses. You may determine that you just need a /60 or /64 for this on smaller networks.
- Point-to-point: According to RFC 6164 and RFC 6547, we can allocate a /64 for each point-to-point link but should use a /127 (provided the hardware supports it).
- Network inside the server: If you require multiple subnets for your management server network, you can allocate from /60. /64 should work in a less complex NOC LAN.
- Network of external servers: /64 allows 264 hosts for public services.
What is IPv6 Address Planning?
Prerequisites: Internet Protocol version 6 (IPv6) and what is IPv6?
A new IP protocol, called Internet Protocol (IP) version 6, is intended to replace IP version 4, which is currently in use and deployed worldwide. The latest IP version, IPv4, has proven to be reliable, easy to implement, and easy to use. It is interoperable and has passed the tests that make the internet a real global utility. However, the original design of IPv4 did not consider the following situations:
- Requirements for IP-level security.
- The rapid expansion of the internet and depletion of IPv4 address space.
- Need for easier auto-configuration and renumbering of network devices.
- Requirements for real-time data delivery also called quality of service.
With the help of methods such as Network Address Translation and private address spaces, IPv4’s life has been extended (NAT). While these methods appear to extend the address space and accommodate traditional client/server configurations, they do not meet the demands of increasing IP addresses. IP address translation, pooling, and temporary assignment techniques cannot be used to connect to always-on environments (such as private internet via broadband, cable modem, or DSL). Additionally, plug-and-play requirements for consumer Internet devices are in addition to address requirements. The IPv6 address space offers more addresses but should be used with caution. You can successfully deploy IPv6 using your existing IPv4 infrastructure. Converting from IP version 4 to IP version 6 is still possible today with proper planning and design.