B-1
Appendix A
Network Address Translation
This section is required only for system programmers who need low level ac-
cess to the Network Address Translation (NAT) Layer. This API does not ap-
ply to sockets application programming.
This section describes functions that are callable from the kernel layer. Users
should familiarize themselves with the operation of the operation of llEnt-
er()/llExit() functions before attempting to use the APIs described in this sec-
tion.
NAT has a unique status in the stack software in that it can be an integral part
of programming at both the user and kernel levels, or can be entirely redundant
and even purged from the stack build.
This section describes the operation of the Network Address Translation soft-
ware included in the TCP/IP stack, how to configure it, how to install port map-
pings, and how to program proxy filter routines to support protocols like FTP.
Topic
Page
B.1
NAT Operation
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B.2
NAT Port Mapping
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B.3
NAT Proxy Filters
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Appendix B