Network Address Translation
Each connection has a set of original addresses and reply addresses, which initially start out the same. NAT in Netfilter is implemented by simply changing the reply address, and where desired, port. When packets are received, their connection tuple will also be compared against the reply address pair (and ports). Being fragment-free is also a requirement for NAT. (If need be, IPv4 packets may be refragmented by the normal, non-Netfilter, IPv4 stack.)
Read more about this topic: Netfilter
Famous quotes containing the words network, address and/or translation:
“Parents need all the help they can get. The strongest as well as the most fragile family requires a vital network of social supports.”
—Bernice Weissbourd (20th century)
“Take a red book called TELEPHONE,
size eight by four. There it sits.
My red book, name, address and number.
These are all people that I somehow own.
Yet some of these names are counterfeit.”
—Anne Sexton (1928–1974)
“Any translation which intends to perform a transmitting function cannot transmit anything but information—hence, something inessential. This is the hallmark of bad translations.”
—Walter Benjamin (1892–1940)