Книга: Iptables Tutorial 1.2.2

AH/ESP match

AH/ESP match

These matches are used for the IPSEC AH and ESP protocols. IPSEC is used to create secure tunnels over an insecure Internet connection. The AH and ESP protocols are used by IPSEC to create these secure connections. The AH and ESP matches are really two separate matches, but are both described here since they look very much alike, and both are used in the same function.

I will not go into detail to describe IPSEC here, instead look at the following pages and documents for more information:

• RFC 2401 - Security Architecture for the Internet Protocol

• FreeS/WAN

• IPSEC Howto

• Linux Advanced Routing and Traffic Control HOW-TO

There is also a ton more documentation on the Internet on this, but you are free to look it up as needed.

To use the AH/ESP matches, you need to use -m ah to load the AH matches, and -m esp to load the ESP matches.

Note In 2.2 and 2.4 kernels, Linux used something called FreeS/WAN for the IPSEC implementation, but as of Linux kernel 2.5.47 and up, Linux kernels have a direct implementation of IPSEC that requires no patching of the kernel. This is a total rewrite of the IPSEC implementation on Linux.

Table 10-8. AH match options

Table 10-9. ESP match options

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