Browse Definitions :
Definition

RFC 1918

Request for Comment 1918 (RFC 1918), “Address Allocation for Private Internets,” is the Internet Engineering Task Force (IETF) memorandum on methods of assigning of private IP addresses on TCP/IP networks.

Along with NAT (network address tunneling), RFC 1918 facilitates expansion of the usable number of IP addresses available under IPV4, as a stopgap solution to prevent the exhaustion of public IPs available before the adoption of IPV6. It’s not necessary to register private IPs with a Regional Internet Registry (RIR), which simplifies setting up private networks.

RFC 1918 was used to create the standards by which networking equipment assigns IP addresses in a private network. A private network can use a single public IP address. The RFC reserves the following ranges of IP addresses that cannot be routed on the Internet:

  • 10.0.0.0 - 10.255.255.255 (10/8 prefix)
  • 172.16.0.0 - 172.31.255.255 (172.16/12 prefix)
  • 192.168.0.0 - 192.168.255.255 (192.168/16 prefix)

IP addresses within these ranges can be assigned within a private network; each address will be unique on that network but not outside of it. Private IP addresses can't be communicated with directly by external computers because they are not globally unique and, as such, not addressable on the public Internet.

Computers on the inside of the network can communicate with the Internet through NAT.  NAT translates an IP address used within one network to a different IP address known within another network. Typically, a company maps its local inside network addresses to one or more global outside IP addresses and unmaps the global IP addresses on incoming packets back into local IP addresses.

This was last updated in October 2020

Continue Reading About RFC 1918

Networking
Security
  • timing attack

    A timing attack is a type of side-channel attack that exploits the amount of time a computer process runs to gain knowledge about...

  • privileged identity management (PIM)

    Privileged identity management (PIM) is the monitoring and protection of superuser accounts that hold expanded access to an ...

  • possession factor

    The possession factor, in a security context, is a category of user authentication credentials based on items that the user has ...

CIO
  • Systems Modeling Language (SysML)

    Systems Modeling Language (SysML) helps teams design, develop, test and deploy complex physical systems.

  • business process reengineering (BPR)

    Business process reengineering (BPR) is a management practice in which business processes used are radically redesigned to ...

  • innovation management

    Innovation management involves the process of managing an organization's innovation procedure, starting at the initial stage of ...

HRSoftware
  • employee resource group (ERG)

    An employee resource group is a workplace club or more formally realized affinity group organized around a shared interest or ...

  • employee training and development

    Employee training and development is a set of activities and programs designed to enhance the knowledge, skills and abilities of ...

  • employee sentiment analysis

    Employee sentiment analysis is the use of natural language processing and other AI techniques to automatically analyze employee ...

Customer Experience
  • customer profiling

    Customer profiling is the detailed and systematic process of constructing a clear portrait of a company's ideal customer by ...

  • customer insight (consumer insight)

    Customer insight, also known as consumer insight, is the understanding and interpretation of customer data, behaviors and ...

  • buyer persona

    A buyer persona is a composite representation of a specific type of customer in a market segment.

Close