Glossary

ASN

Autonomous System Number

The unique number that identifies your network on the internet. You need one to announce your own IP addresses with BGP and to be multihomed.

What is an ASN?ASN Registration

BGP

Border Gateway Protocol

The protocol networks use to tell each other which IP addresses they can reach. Announcing your own address space requires a BGP session with your internet provider.

BGP ConsultancySetting up your ASN

BYOIP

Bring Your Own IP

A feature of cloud providers that lets you use your own address block in their network. Our leased blocks work with BYOIP on the large cloud providers, and bringing a block is usually cheaper than paying the cloud provider for that many public IPs.

IP Address Lease

CIDR notation

and the subnet mask

A short way to write a block of IP addresses, such as 192.0.2.0/24. The part before the slash is the first address. The number after it says how big the block is: the smaller the number, the more addresses. A /24 is 256 addresses. The same size can also be written as a subnet mask, such as 255.255.255.0.

Subnet Calculator

Geofeed

A text file in which a network publishes the country, region and city of its IP addresses, so that geolocation databases can read it. It is linked from the address block's entry in the RIPE Database.

What is a geofeed?Geofeed GeneratorIP geolocation guide

IP geolocation

Working out which country and city an IP address is used in. The address itself holds no location, so providers keep databases that estimate it, and websites look their visitors' addresses up in them.

How IP Geolocation Works and How to Correct It

IRR

Internet Routing Registry

A database that records which AS number is allowed to announce which route, that is which block of IP address space. Many network providers read it when deciding whether to accept an announcement.

Setting up your ASN

LIR

Local Internet Registry

A member of a Regional Internet Registry that can request and hold PA (Provider Aggregate) IP addresses, and sponsor AS numbers and PI (Provider Independent) space for others. We are a RIPE NCC member LIR.

What is an LIR?Managed LIR

LoA

Letter of Authorisation

A letter from the holder of an address block that authorises your upstream provider to announce it for you. We provide one on request for as long as the contract runs, if your provider requires it.

IP Address Lease

Multihoming

Connecting a network to two or more upstream providers, so that traffic keeps flowing if one of them fails. To set it up you need your own AS number and BGP.

What is an ASN?BGP Consultancy

PA space

Provider Aggregate

Address space allocated to an LIR, which hands parts of it to its customers. It is the kind of space we lease.

What is IP address leasing?IP Address Lease

PI space

Provider Independent

Address space assigned to an end user through a sponsoring LIR and registered to the end user. The RIPE rules do not allow renting it out.

Resource Sponsoring

RIR

Regional Internet Registry

One of five organisations that look after IP addresses and AS numbers for a part of the world: the RIPE NCC, ARIN, APNIC, LACNIC and AFRINIC. We work in the RIPE NCC region.

What is an LIR?

Reverse DNS delegation

Handing the control of the reverse zone of an address block to the one who uses the addresses, who then keeps its records on their own DNS servers. Our leases hand it over to you.

IP Address Lease

RPKI and ROA

Resource Public Key Infrastructure and Route Origin Authorisation

A signed ROA says which AS number may announce an address block, and helps stop other networks announcing your addresses. We set up the ROA for every lease.

Setting up your ASNIP Address Lease

Sponsoring LIR

An LIR that requests resources such as an AS number or PI space for an end user and signs a contract with them. The end user does not have to become a RIPE NCC member.

Resource SponsoringASN Registration