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The address block fc00::/7 has been reserved to use for unique local addresses.ĭale Liu. Using unique local addresses can help prevent external systems from having direct access to your internal systems. They are not routable on the global Internet. These addresses can only be used within a specified organization. They are similar to “private” IPv4 addresses. Unique local addresses are a set of addresses that are intended for use in internal networks. So, during a normal startup process, an IPv6 system will obtain a link-local address before it receives a regular, routable IP address. IPv6 system must have a link-local address in order for some of internal protocol functions to work properly. In IPv6 link-local addresses may be assigned by the stateless address autoconfiguration process.
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The bottom 64 bits used for the address are random. In IPv6, the address block fe80::/64 has been reserved for link-local addresses. Link-local addresses allow you to have network connectivity until another more suitable address can be obtained. These addresses were used by the DHCP autoconfiguration service on a system when a DHCP address could not be obtained. They existed in the address block 169.254.0.0/16. Link-local addresses also existed in IPv4. Routers will not route link-local addresses. Link-local addresses are intended to only be used on a single network segment or subnet. The loopback address in IPv4 is 127.0.01. It is an internal address that routes back to the local system. The loopback address, also called localhost, is probably familiar to you. We will cover the loopback address, link-local addresses, and unique local addresses. These addresses or groups of addresses serve very specific function. There are several special addresses in IPv6.
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#What is loopback windows
Derrick Rountree, in Windows 2012 Server Network Security, 2013 IPv6 Special Addresses