Classless Inter-Domain Routing (CIDR) Tools

Everything about this Classless Inter-Domain Routing address block

Base information

Address Block 2001:5::/32
First address 2001:5::
Last address 2001:5:ffff:ffff:ffff:ffff:ffff:ffff
Hosts in range 79 228 162 514 264 337 593 543 950 336
Mask bits 32

IANA Special-Purpose Registry

This CIDR is in a special-purpose block reserved by IANA for special purposes.

Address Block 2001:5::/32
Purpose EID Space for LISP (Managed by RIPE NCC)
Allocation Date September 2016
Termination Date September 2019
Source true
Destination true
Forwardable true
Globally Reachable true
Reserved by protocol true
Defined in RFC [RFC7954]
  • According to the 3+3 Plan outlined in [RFC7954], the termination date can be postponed to September 2022.
  • Can be used as a multicast source as well.
  • To be used as EID space by routers enabled by LISP [RFC6830].


REST API on request


Free online tools focused on reliability and speed.
For developers, we offer free public REST APIs: IP to geolocation, hostname information, user-agent string parser, identicon generator and more

CIDR information and calculator

Analyze a CIDR

Example: or 2001:db8::/32