At 4:09 AM +0200 9/24/00, Fred Baker wrote:
A VPN is, by my definition, any case where one overlays the global
Internet with another private Internet using tunneling. Tunneling
procedures today include MPLS, IPSEC, IP/IP, GRE/IP, and probably
several others.
Others might have a very different definition of VPN. The "P" in
"VPN" stands for "privacy", which requires encryption. Without a
lower layer of encryption, it is trivial for someone to snoop on your
MPLS or IP/IP or GRE/IP tunnel.
The things described above are VINs, or Virtual Isolated Networks
(thanks to Tero Kivenen for the term). VINs have useful features, but
privacy is not one of them.
The most popular IETF standard for VPNs is IPsec using ESP.
--Paul Hoffman, Director
--VPN Consortium