We are indebted to numerous individuals who enabled us to implement our firewall using off-the-shelf components: John Ioannidis, Neil Haller, MIT project Athena, and Steve Crocker, Marcus J. Ranum, and others at Trusted Information Systems. Because these individuals made their respective software available for non-commercial use, we were able to focus on the design and policy needs of a research environment. In this spirit, we have made our locally-developed software available for anonymous FTP from gregorio.Stanford.EDU in /pub/firewall/.
Our firewall development resulted from enormous effort by several other members of our research group, particularly Ken Duda, Hugh Holbrook, and Mark Steiglitz. This paper benefited greatly from feedback of our colleagues---particularly Mary Baker, Stuart Cheshire, and Craig Partridge.
The authors were supported by ARPA under contract DABT63-91-K-0001. Michael Greenwald was supported by a Rockwell Fellowship. Sandeep Singhal was supported by a Fannie and John Hertz Foundation Fellowship.