dns rfc

http://www.ietf.org/rfc/rfc1035.txt

cryptography

Elona Dunin's website. Has a good list of references.
http://www.elonka.com/

rfc reference list

http://dret.net/rfc-index/titles

radius and kerberos

Radius and Kerberos are two different things and are often mistaken to
be rivals.
http://groups.google.com/group/comp.protocols.kerberos/browse_thread/thread/ac3c6e606c48a72a/c575caa3d41e0fad%23c575caa3d41e0fad?sa=X&oi=groupsr&start=0&num=3