Resource Quality Assistance

Regional Internet Registries (RIRs) distribute IP address space and can make no claims whatsoever about routability. This is because routability is the domain of ISPs and other network operators. The RIPE NCC does however recognise this problem and the Internet community’s concern about the quality of allocated and assigned IP address blocks.


To reduce routability problems, the RIPE NCC:

  • Announces pilot prefixes of every newly allocated IP address block before making allocations from this block.
  • Quarantines returned IP address space before it is allocated or assigned to another organisation.
  • Announces new allocations from the IANA to the RIPE NCC to Local Internet Registries (LIRs), the RIPE community and other stakeholders as soon as possible.
  • Provides an FAQ section on our website that provides information about filtering, how it can be avoided and what actions can be done if a range appears to be filtered.
  • Provides information in our training courses about responsible filtering and what to do if a legitimate range is mistakenly filtered.
  • Has established internal procedures to assist LIRs:
  • Provide information about tools to identify where the range is filtered
  • Provide available contact details of the organisation that filter to the affected LIR/ISP
  • Help to establish a direct communication between both parties


We do this because many Internet Service Providers (ISPs) and network operators use filtering to block out address space such as unallocated, private or reserved IP address blocks (“bogon space”) and blacklisted address space. This is done to reduce security incidents such as DDoS attacks or spamming.

If these filters are not kept up-to date this can result in blocking legitimate traffic and reachability problems for ISPs and their customers.