[dns-operations] "EarthLink Criticized for DNS Redirects"
jabley at ca.afilias.info
Mon Sep 18 15:20:18 UTC 2006
Le 2006-09-18 à 09:54, Barry Greene (bgreene) a écrit :
> Yes, that is the practice turned policy that I'm talking about.
Thanks for the clarification.
It may be useful to note that it's a recommendation for ISPs, the
next time you mention it. Your comment 'much like Canada who has all
customers go through their "port 25" infrastructure' makes it sound
like some kind of draconian centralised government control of
packets. Although some big residential ISPs in Canada do this, many
residential ISPs do not (and I haven't yet heard of business-grade
internet access services that implement it, although there may well
The trouble with 25/tcp redirection is that it breaks mail submission
from clients to mail services not run by their ISPs. Since mail
clients have widely-available alternatives these days, however (most
clients will let you specify a port) this turns out to be a non-issue.
There's an unfortunate analogue between the 25/tcp-overloading and
the DNS, however. There are a big class of requests sent to 53/udp
which are suitable for redirection to a local cache, but there are
many notable exceptions.
Maybe it's reasonable to look at a couple of examples of things that
are really unsuitable for redirection (AXFR/IXFR and UPDATE, say) and
to standardise alternate ports for them to listen on.
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