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Re: [Asrg] Re: RMX evaluation

2003-05-09 07:43:55
From: Hadmut Danisch <hadmut(_at_)danisch(_dot_)de>

...
It is very astonishing that it is Vernon who brings that proposal.
Concerning Vernon's objections against RMX, there is no difference
between RMX and this proposal. So why should those objections 
apply on RMX, but not on that proposal? The effect that use of 
a certain domain as a sender address will be limited to some
IP addresses as well. It will require DNS queries as well. 
It will require hotmail, yahoo, aol users to deliver through
the hotmail/yahoo/aol relays as well. So what's the point in 
quoting that proposal in context of the objections against RMX?

What is astonishing about trying to be honest and forthright?  Those
of my objections to RMX that are also relevant to Paul's notion
certainly apply.  I did write:

] - I do not like this scheme, because I do not agree with the goal of
l    forcing people to use the same going as incoming ISPs.


The advantage of Paul Vixie's proposal is, that it doesn't require
a new DNS RR type. 

The disadvantage is, that it is error prone and takes a high overhead:

There are providers who provide services for 20..2,000,000 domains. 
Since in this proposal the domain zone tables must list every single
mail relay, all zone tables must be updated if the provider installs
an additional relay. 

I do not understand how which files must be edited differs among the
RMX varients.  I also do not understand how one can make any general
claim in that regard because the most popular DNS server implementations
have features like "include" statements to include other files.

                     If the provider does have access to the zone
tables, this is just a heap of work. If the provider does not have
access to the zone tables, then it is a severe overhead and delay
to inform all the domain owners and ask them to update their tables.

I do not understand how a provider that should be controlling RMX-like
records is likely to not have access to teh zone tables.

When writing your domain table, you need a detailed list of the 
relays your provider has. At least you need to know the number of
relays. In reality, it would certainly look like this:

.. MX  relay0.provider.com
       relay1.provider.com
       relay2.provider.com

But you will always have to update the list if the provider uses
one more relay than you have listed. 

That's why RMX uses an indirection step through the provider's 
APL records. It's a design criterion to avoid this overhead and
delay.

An example contrasting the records for the two proposals might
make that clear.


Vernon Schryver    vjs(_at_)rhyolite(_dot_)com
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