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CCNA 1.15: Compare and contrast IPv6 address types (Global unicast, Unique local, Link local, Multicast, Modified EUI 64, Autoconfiguration, Anycast)

Overview:

IPv6 address types consist of unicast and multicast addresses along with anycast addresses. With IPv6, an interface is expected to have multiple addresses. It also listens to various multicast addresses. IPv4 addresses are either unicast, multicast or broadcast.  In IPv6, broadcast addresses no longer exist.

 

Study notes:

  • Unicast - uniquely identifies an interface. transmission to a single recipient.
    • Link local - scope is limited to directly attached network (link)        FE80::/10
    • Unique local - technically, scope global, but it's really limited to your network. similar to IPv4 private IP addresses.    FC00::/7
    • Global unicast - scope is global. similar to IPv4 public IP addresses.        2000::/3
  • Multicast - transmission to several recipients.
    • Assigned        FF0s::/8
    • Solicited Node        FF02::1:FF00:0000/104
  • Anycast - a collection of devices share the same IPv6 address.  transmission is to the closest address topographically
    • identical to unicast. only difference is administrative.
  • Modified EUI 64
    • EUI-64 - Extended Unique Identifier - a host can automatically assign itself a unique 64-bit IPv6 interface identifier without the need for manual configuration or DHCP
    • Modified - the 7th bit is the universal/local bit. 1 for universal, 0 for local. purpose is to allow development of future technology that can take advantage of interface identifiers with universal scope
  • Autoconfiguration - similar to DHCP in IPv4. Routers running IPv6 can give the network prefix and gateway address to clients looking for an IPv6 address.

Links:

IPv6 overview on Cisco.com


   3 Comments


  1. youssef leknizi
      December 16, 2018

    i think for unique local the network prefix is FEC0::/10

    • Joe Barger (CCNP/CCDP)
        December 16, 2018

      FECO::/10 was previously used for site-local addresses, but site-local addresses were deprecated in 2004.
      In 2005, the address block FC00::/7 was reserved for unique local addresses, which improves upon the issues that arose with site-local addresses.

      Check out more in RFC3879 and on Wikipedia

  2. youssef leknizi
      December 17, 2018

    thank u joe for the information

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