NRL IPv6 Software Distribution

Release "Alpha-2" 19 January 1996


The NRL IPv6 Software Distribution is a reference implementation of IPv6 inside the 4.4-Lite BSD Networking software. It is freely distributable and usable for commercial and non-commercial purposes as long as the NRL and UC Berkeley license terms are adhered to. The developers would like to see this software be widely distributed and used.

We have tested this software on SPARC systems using the UC Berkeley 4.4 BSD UNIX operating system (with 4.4-Lite enhancements added in). We have also tested this software on i486/i586 systems using BSDI for the non-networking software and the 4.4-Lite distribution for the networking software. We believe it is easily portable to similar operating systems (e.g. NetBSD, FreeBSD, SunOS 4.1.x). This implementation includes kernel networking software, a small IPv6 support library, and several applications (e.g. telnet, telnetd, ping, tftp, tftpd, socktest, netstat, ifconfig, ping, route, tcpdump) modified to support IPv6. This distribution also includes software for IPv4 and IPv6 security using the mechanisms defined in RFC-1825 through RFC-1829. Finally, we have a very neat and useful kernel addition in the form of PF_KEY, a kernel subsystem to store and manage cryptographic keys. There are manual pages for the modified and new software, but they might not yet be as detailed as one might like.

This "alpha-2" quality release of the IPv6 software is intended for use by kernel hackers and implementers who want to get early access and experience with IPv6. If you aren't an experienced kernel hacker or builder, then you probably only want to look at but not actually use our software. Use at your own risk. It is complete enough to use for experimenting but it is not entirely complete. In some areas this is because the IPv6 specifications are not yet stable. We have more features working now than the original release did. These include:


There have been personnel changes within the IPv6 group at NRL, but development work does continue. NRL is willing to consider accepting contributed changes as long as those changes are freely distributable. If you have contributions to offer, please send email to the developers at:


There are a modest number of known bugs (described in the BUGS file, which read). Because only limited testing has occurred, there are probably more as yet undiscovered bugs. If you find bugs, please do the best you can. The alias is probably still up, though we cannot guarantee any results.


The NRL IPv6 software development team included, (in alphabetical order :-), Randall Atkinson, Ken Chin, Dan McDonald, Craig Metz, & Bao Phan. Most of the code has had more than one person working on it over the past year or so.

This work was initially sponsored by the Information Security Program Office (PD 71E), US Space & Naval Warfare Systems Command (SPAWAR). More recently, our work has been sponsored by the Computing Systems Technology Office, Advanced Research Projects Agency (ARPA/CSTO). We really appreciate their sponsorship of our efforts to bring the world IPv6 software (including cryptographic security).


UNIX is a trademark of Novell.
NRL is a trademark of the US Naval Research Laboratory
All other trademarks are property of their respective owners.


This software distribution (including its documentation) is copyrighted. See the COPYRIGHT file in this directory and also the various copyright notices in the software itself for more information on this and on the applicable license terms. The key engine has a patent pending but has been licensed on similar no-cost terms because ARPA has written that into our Statement of Work, see the netinet6/key.c file for more information on that license.