What can I do if my address block is filtered?

If you think your address blocks have been filtered, it is very important to determine how your IP addresses are being blocked:

Run a traceroute to see if the new IP addresses are consistently blocked along the same network path. We also advise you to test forward and reverse paths. The use of technology like the Routing Information Service (RIS) is highly recommended to assist in identifying routing conditions for prefixes under test. RIS is a RIPE NCC project that collects and stores Internet routing data from several locations around the globe. One of the services we provide de-bogonises new IP address blocks to test reachability and view statistics for the visibility of new address blocks over the Internet.

Do a search on your IP addresses and contact organisations that appear to be blocking you. You may be blocked by a technology called DNSBL (DNS-based Blackhole List), due to malicious activities of one of your customers.

If you set up your servers to block bogon IP address ranges, your own firewall might be blocking the new IP addresses by default. To avoid blocking potential new customers, stay on top of changes to that list because new IP address ranges are constantly released.

Use a looking glass service as part of the diagnostic toolset to detect network filters.

Be sure to contact networks that are blocking your IP addresses and request that they remove the filter that is affecting your network traffic. Look up their contact address in the relevant Regional Internet Registry (RIR) whois database. If the contact address is invalid, please notify the appropriate registry.