IP masquerading works well for all IP protocols that are based on TCP, UDP, or ICMP, and that communicate exclusively over ports. These uncomplicated protocols include, among others, the basic protocol of the World Wide Web: HTTP.
Although some IP protocols do use TCP or UDP, they do not communicate exclusively through ports. Protocols of this type require special treatment during IP masquerading. Protocols supported by IP masquerading in the device and requiring special treatment include:
- FTP (using the standard ports)
- PPTP
- IPSec
- IRC
