uceprotect.net is a DNS blacklisting service that is comprised of three distinct zones: dnsbl-1.uceprotect.net, dnsbl-2.uceprotect.net, and dnsbl-3.uceprotect.net. Each zone has different listing criteria, all of which are extremely important to understand before using any zone within the service. While DNS blacklists by nature can be controversial, uceprotect.net is perhaps one of the most controversial of them all.
dnsbl-2.uceprotect.net is uceprotect.net’s secondary level zone. Listing in useprotct.net is somewhat unique compared to other DNS blacklists, due to the three distinct listing zones that are made available. Zones range from level one to level thee. Level one contains individual IP addressees, level two listings are escalations to containing subnets surrounding level one addresses, and level three, contains even larger subnets surrounding level two listings. This listing criteria essentially covers the broadest range of IP addresses possible.
If a set of IP addresses is seen spamming, it will start with a listing in the level one list. If within seven days, that spam has not stopped, the listing will escalate to contain much broader ranges of IP addresses. Essentially a level one listing may contain up to 255 IP addresses; if that is escalated to a level two listing, the number of IP addresses may be as high as tens of thousands. Finally, if still no action is taken against the spammers, a level three listing can potentially block IP ranges that contain entire service providers, which could mean hundreds of thousands of listed IP addresses.