5. Encrypting Network Traffic

This section is in preparation. See the section Release Notes for a planned roadmap.

I will just give you the necessary links to find other documentation on the following packages:

• CIPE (Cryptographic IP Encapsulation) by Olaf Titz ( Olaf.Titz@inka.de) ships with the International Kernel Patch (see section Obtaining and Installing the International Kernel Patch)---at least the kernel modules. The userspace tools needed are available from http: //sites.inka.de/~bigred/devel/cipe.html. Latest version is 1.3.0 (Apr 1999). There is also a mailing list dedicated to CIPE. You can subscribe to it by sending a message with the single line subscribe cipe-l in its body to majordomo@inka.de.

• FreeS/WAN (IPSec implementation) is available at www.freeswan.org. Current version is 1.1 (Oct 1999), which is reported to work well with 2.2 kernels (1.0 does not).

  FreeS/WAN is a Linux based implementation of the IETF IPSec standard. If you want to know all there is to know about IPSec, see the RFC's concerned with it, esp. the famous RFC's 2401: Security Architecture for the Internet Protocol thru 2412: The OAKLEY Key Determination Protocol. Note, however, that these documents add up to 20,000 lines of pure text or 800K.

  This package is very complex indeed, but as it is based on an IETF standard, it inter-operates with many other (commercial) VPN products, including PGPnet. This makes it the single obvious choice for admins that need extensive cross-platform capabilities.

  There is a very active mailing list you can subscribe to, if you send a message with the single line subscribe linux-ipsec in the body of the message to majordomo@clinet.fi.

• ENSkip is an implementation of Sun's SKIP protocol. Its advantages over other approaches include a long history, which implies a relative stableness, and good cross-platform capabilities (at least within the Unices department). You can find its homepage at http://www.tik.ee.ethz.ch/~skip/

• VPND is another approach out there for Linux (and FreeBSD). You can fetch additional information from its homepage at http://sunsite.auc.dk/vpnd/. There is also a mailing list, which you can subscribe to if you send an empty message to vpnd-subscribe@sunsite.auc.dk and follow the directions given in the reply.

• SSH (Secure Shell) can also be employed to establish an encrypted tunnel between two hosts. There is a VPN mini-HOWTO already covering the setup, but it is rather dated (Aug 1997).