SOLVED: What Are The Loopback Addresses in IPv6 IPv4 and What Are All The Other Special Use IP Ranges?

If you are working on a network you are going to see some IPv6 traffic and it can get quite confusing.  A “loopback” is an address that causes the traffic to be sent to the same interface is was sent out on on the localhost.

what-is-loopback-ipv4-ipv6-test-network-cardUsage of loopback addresses are particularly popular with developers and anyone in IT performing network tests.  For instance, if you think your Network Card is failing you can try:


and if you don’t see a reply with a TIME<1ms, your card or TCP/IP stack likely has a problem.  If you are on a PC that supports IPv6 (all Windows 10, 8, 7 and Vista PC’s), you can try the same test using:

PING ::1

Below are all of the loopback IP addresses:

  • IPv6 = 0:0:0:0:0:0:0:1
  • IPv6 = 0:0:0:0:0:0:0:0
  • IPv6 = 0:0:0:0:0:ffff:7f00:1
  • IPv6 = ::1
  • IPv6 = ::
  • IPv4 = to

Below is a table of all the ‘Special Use’ IP Ranges:             “This” Network            Private-Use Networks            Public-Data Networks            Cable Television Networks            Reserved, subject to allocation          Loopback        Reserved, subject to allocation    Link Local      Private-Use Networks    Reserved, subject to allocation        Reserved but subject to allocation        Test-Net    6to4 Relay Anycast    Private-Use Networks        Network Interconnect Device Benchmark Testing     Reserved, subject to allocation          Multicast, commonly used in multiplayer simulations and gaming and for video distribution.          Reserved for Future Use


Questions or Comments?