Reserverede IP-adresseområder
De adresseblokke, der ikke er almindelige offentlige adresser, fra IANA's registre over specialadresser – og et tjek, der fortæller, hvilken blok en adresse hører til.
100.64.12.7 ligger i 100.64.0.0/10: Delt adresserum (CGNAT).
Specialblokke i IPv4
| Blok | Formål | Defineret i | Kan nås fra internettet |
|---|---|---|---|
| 0.0.0.0/8 | UspecificeretThis network | RFC 791 | Nej |
| 10.0.0.0/8 | Privat netværkPrivate-Use | RFC 1918 | Nej |
| 100.64.0.0/10 | Delt adresserum (CGNAT)Shared Address Space (CGNAT) | RFC 6598 | Nej |
| 127.0.0.0/8 | LoopbackLoopback | RFC 1122 | Nej |
| 169.254.0.0/16 | Link-lokalLink-Local | RFC 3927 | Nej |
| 172.16.0.0/12 | Privat netværkPrivate-Use | RFC 1918 | Nej |
| 192.0.0.0/24 | ProtokoltildelingIETF Protocol Assignments | RFC 6890 | Nej |
| 192.0.2.0/24 | DokumentationDocumentation (TEST-NET-1) | RFC 5737 | Nej |
| 192.31.196.0/24 | AnycastAS112-v4 | RFC 7535 | Ja |
| 192.52.193.0/24 | ProtokoltildelingAMT | RFC 7450 | Ja |
| 192.88.99.0/24 | ReserveretDeprecated 6to4 Relay Anycast | RFC 7526 | Nej |
| 192.168.0.0/16 | Privat netværkPrivate-Use | RFC 1918 | Nej |
| 192.175.48.0/24 | AnycastDirect Delegation AS112 Service | RFC 7534 | Ja |
| 198.18.0.0/15 | BenchmarkingBenchmarking | RFC 2544 | Nej |
| 198.51.100.0/24 | DokumentationDocumentation (TEST-NET-2) | RFC 5737 | Nej |
| 203.0.113.0/24 | DokumentationDocumentation (TEST-NET-3) | RFC 5737 | Nej |
| 224.0.0.0/4 | MulticastMulticast | RFC 5771 | Nej |
| 240.0.0.0/4 | ReserveretReserved for future use | RFC 1112 | Nej |
| 255.255.255.255/32 | BroadcastLimited Broadcast | RFC 919 | Nej |
Specialblokke i IPv6
| Blok | Formål | Defineret i | Kan nås fra internettet |
|---|---|---|---|
| ::/128 | UspecificeretUnspecified Address | RFC 4291 | Nej |
| ::1/128 | LoopbackLoopback Address | RFC 4291 | Nej |
| ::ffff:0:0/96 | OversættelseIPv4-mapped Address | RFC 4291 | Nej |
| 64:ff9b::/96 | OversættelseIPv4-IPv6 Translation (NAT64) | RFC 6052 | Ja |
| 64:ff9b:1::/48 | OversættelseLocal-use IPv4/IPv6 Translation | RFC 8215 | Nej |
| 100::/64 | ReserveretDiscard-Only Address Block | RFC 6666 | Nej |
| 2001::/32 | OversættelseTEREDO | RFC 4380 | Nej |
| 2001:2::/48 | BenchmarkingBenchmarking | RFC 5180 | Nej |
| 2001:db8::/32 | DokumentationDocumentation | RFC 3849 | Nej |
| 2001:10::/28 | ReserveretDeprecated (ORCHID) | RFC 4843 | Nej |
| 2001:20::/28 | ProtokoltildelingORCHIDv2 | RFC 7343 | Ja |
| 2002::/16 | Oversættelse6to4 | RFC 3056 | Nej |
| 3fff::/20 | DokumentationDocumentation | RFC 9637 | Nej |
| 5f00::/16 | ProtokoltildelingSegment Routing (SRv6) SIDs | RFC 9602 | Nej |
| fc00::/7 | Unik lokal (ULA)Unique-Local | RFC 4193 | Nej |
| fe80::/10 | Link-lokalLink-Local Unicast | RFC 4291 | Nej |
| ff00::/8 | MulticastMulticast | RFC 4291 | Nej |
Hentet fra IANA's registre over specialadresser for IPv4 og IPv6 plus multicast og den gamle klasse E. »Kan nås fra internettet« følger IANA's kolonne »globally reachable«. En privat adresse routes aldrig på det offentlige internet.
Denne tekst findes endnu ikke på dansk. Den vises på engelsk, indtil en oversættelse er udgivet.
Not every IP address is meant to be routed on the internet. IANA keeps two special-purpose address registries, one for IPv4 and one for IPv6, listing the blocks set aside for private networks, loopback, link-local use, documentation, benchmarking, protocol translation and other purposes. Together with the multicast ranges and IPv4’s old class E, they are the addresses a router should never accept as ordinary public destinations, often called bogons.
The ones you are most likely to meet: the three private ranges of RFC 1918 (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16) used in almost every home and office network; shared address space 100.64.0.0/10 used by providers for carrier-grade NAT; link-local 169.254.0.0/16 and fe80::/10, which a device gives itself when nothing else configures it; and the documentation blocks (192.0.2.0/24, 198.51.100.0/24, 203.0.113.0/24, 2001:db8::/32) reserved for examples like the ones on this site.
The table is generated from the same registry data this site uses to classify every lookup, and the checker tells you which block an address belongs to, right in your browser.
Ofte stillede spørgsmål
My router's WAN address starts with 100.64. Is that a problem?
It means your provider uses carrier-grade NAT: you share a public IPv4 address with other customers. Browsing works normally, but you cannot open ports to the internet over IPv4. IPv6 or a fixed public address solves it.
Why did my PC get a 169.254.x.x address?
It asked for an address (DHCP) and got no answer, so it assigned itself a link-local address. Check the cable or Wi-Fi connection and the router's DHCP server.
Can I use 192.0.2.0/24 or 2001:db8::/32 in my network?
You should not. They are reserved for documentation, so examples never collide with real networks. Use the private ranges, or unique local addresses (fd00::/8) for IPv6.