As public IPv4 addresses become more scarce, multiple-layers of NAT will be required to sustain the Internet for years to come. Use of Large Scale NAT (LSN) systems by service providers will cause problems for many applications. Today there are many security filtering systems that use lists of public IPv4 addresses to identify "undesirable" hosts on the Internet. As more ISPs deploy LAN systems the effectiveness of these IPv4 filtering systems will diminish.
There are many reputation filtering vendors on the market and more being offered every quarter. Ask Continuums to help you choose the reputation filtering solution to protect your enterprise.