Cymru Bogons Blacklist Check & Removal Process

How to check if you are listed in Cymru Bogons?

  • DNS Lookup: If your IP is 1.2.3.4, You can query: nslookup 4.3.2.1.bogons.cymru.com
  • If it returns 127.0.0.2, your IP is currently considered a bogon.
  • As the official website doesn’t provide a way to check, we also suggest using third‑party tools such as MXToolbox to confirm your status.

How to remove a Domain/IP address from Cymru Bogons?

  • You cannot request a manual delisting from Cymru Bogons. The list is updated automatically based on global IP registrations.
  • Removal Method A: The IP is officially assigned
    • If your ISP was recently assigned a new block of IP addresses, Team Cymru will automatically remove those IPs from the Bogon list once the assignment is reflected in the official registry (IANA/RIPE/ARIN).
    • This usually happens within a few days of the allocation.
  • Removal Method B: Fix your Server Configuration (The most common fix)
    • If you are seeing “Bogon” errors, it usually isn’t because the list is wrong—it’s because your server is leaking its private internal IP address to the outside world.