[26610] in North American Network Operators' Group
Re: Selection of Appropriate Local SMTP Relay
daemon@ATHENA.MIT.EDU (John R. Levine)
Mon Jan 10 09:03:43 2000
Date: 10 Jan 2000 09:01:49 -0500
Message-ID: <20000110140149.6333.qmail@xuxa.iecc.com>
From: johnl@iecc.com (John R. Levine)
To: jabley@patho.gen.nz
In-Reply-To: <20000110215558.A13264@patho.gen.nz>
Cc: nanog@merit.edu
Errors-To: owner-nanog-outgoing@merit.edu
>Selection of Appropriate Local SMTP relAy (SALSA :)
> An alternative is to provide a method for a mail client to discover a
> suitable local smart relay in some dynamic fashion. This requires some
> ubiquitous, global, standard database which every operator uses...
> ... like the DNS.
That's much too complicated. What we need are some well-known IP
addresses, analogous to well-known ports, that are not routable on the
global Internet, but that are assigned to standard services within
each network, e.g.:
10.255.255.1 - DNS server
10.255.255.2 - SMTP server
10.255.255.3 - SOCKS server
10.255.255.4 - Web proxy
(Probably it's not a good idea to use network 10 here, better to
reclaim a /24 from the swamp or allocate a fresh one.)
Now you set up your mail client to use 10.255.255.2 for SMTP, and wherever
you're connected, it'll be the local SMTP server.
>Advantages
0. Works with all existing mail clients, no code changes needed, just a
one-time configuration. Once this is widely accepted, MTAs would
ship with it as the factory default.
Some people have suggested something similar with a well-known-service
pseudo-TLD that each network's DNS servers would serve up with the
appropriate values for that network, e.g.
smtp.wks
socks.wks
webproxy.wks
I like that less because, as previously noted, lots of people never
change their DNS config when they switch ISPs or roam, so they'd get
the info for the wrong network. Better to use IPs which you know will
be routed by the routers for the network to which you are actually
connected.
This seems to me so simple that I don't understand why we didn't do it
five years ago.
--
John R. Levine, IECC, POB 727, Trumansburg NY 14886 +1 607 387 6869
johnl@iecc.com, Village Trustee and Sewer Commissioner, http://iecc.com/johnl,
Member, Provisional board, Coalition Against Unsolicited Commercial E-mail
