Browse Prior Art Database

On Many Addresses per Host (RFC1681)

IP.com Disclosure Number: IPCOM000002519D
Original Publication Date: 1994-Aug-01
Included in the Prior Art Database: 2000-Sep-12
Document File: 5 page(s) / 11K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

S. Bellovin: AUTHOR

Abstract

This document was submitted to the IETF IPng area in response to RFC 1550. Publication of this document does not imply acceptance by the IPng area of any ideas expressed within. Comments should be submitted to the big-internet@munnari.oz.au mailing list.

This text was extracted from a ASCII Text document.
This is the abbreviated version, containing approximately 26% of the total text.

Network Working Group S. Bellovin

Request for Comments: 1681 AT&T Bell Laboratories

Category: Informational August 1994

On Many Addresses per Host

Status of this Memo

This memo provides information for the Internet community. This memo

does not specify an Internet standard of any kind. Distribution of

this memo is unlimited.

Abstract

This document was submitted to the IETF IPng area in response to RFC

1550. Publication of this document does not imply acceptance by the

IPng area of any ideas expressed within. Comments should be

submitted to the big-internet@munnari.oz.au mailing list.

Overview and Rational

Currently, most hosts have only one address. With comparatively rare

exceptions, hosts as hosts -- as opposed to hosts acting as routers

or PPP servers -- are single-homed. Our address space calculations

reflect this; we are assuming that we can estimate the size of the

address space by counting hosts. But this may be a serious error. I

suggest that that model may -- and should -- change.

For the ideas outlined below, I do not claim that multiple addresses

per host is the only or even necessarily the best way to accomplish

the goal. I do claim that my ideas are at the very least plausible,

and that I expect that many of them will be tried.

Encoding Services

More and more often, services are being encoded in the host name.

One can fetch files from ftp.research.att.com, look up an IP address

on ns.uu.net, synchronize clocks from ntp.udel.edu, etc. Should this

practice be generalized to the IP address domain?

In some cases it would be a very good idea. Certain services need to

be configured by IP address; they are either used when the DNS is

being bootstrapped (such as in glue records and root server cache

records), or when its unavailable (i.e., when booting after a power

hit, and the local name servers are slower to reboot than their

diskless clients.

Security is another reason, in some cases. Address-based

authentication is bad enough; relying on the name service adds

another layer of risk. An attacker can go after the DNS, in that

case. A risk-averse system manager might prefer to avoid the extra

exposure, instead granting privileges (i.e., rlogin or NFS) by

address instead of name. But that, of course, leads to all the usual

headaches when the location of the service changes. If the address

for the service could be held constant, there would be much more

freedom to move it to another machine. One way to do that is by

assigning the serving host a secondary address.

A related notion comes from the need to offer different views of a

service from a single host. For example, research.att.com has long

offered two distinct FTP archives, with slightly different access

policies. It would be nice if both could live on the same machine,

wit...