IP Addressing Problems: on my laptop

[shapj@us.ibm.com]

It was never the case that an IP address mapped to a host.  It was rather
the case that an IP address mapped to a host *interface*.

To work around this, the CNAME (canonical name) entry was added to DNS.  In
theory, you are supposed to run reverse DNS on IP number w.x.y.z by doing a
DNS lookup on z.y.x.w.in-addr.arpa, examine the CNAME record, and thereby
obtain the host name.

Please note, however, that at no time did CNAME give you anything better
than the *alleged* host name in practice.

Further, please note that the trend in web server functionality has been to
completely divorce host name from IP address.  In newer web clients, for
example, a.com and b.com may actually be mapped to the same IP address.
The client provides the name of the host in the protocol exchange, and the
web server uses this for virtual hosting.


My sense, in the end, is that you aren't really after an IP address, nor
even a unique host identifier.  What you *really* seem to be after is a
unique *session* identifier.  I can imagine running independent sessions on
a server and wanting to be able to connect to such independently.  Unique
session identifiers can certainly be built, but it isn't going to come from
the host.



shap