Re: The internet architecture

[Masataka Ohta <mohta at necom830.hpcl.titech.ac.jp>]

Stephane Bortzmeyer wrote:

>>The problem to represent a host with raw addresses is that they
>>can't represent a host with multiple addresses,

> OK

>>supporting of which is useful and often required, for example, for
>>DNS and SMTP clients.

> "Required"? Neither DNS nor SMTP requires that. I'm not even sure it
> is good practice.

If an SMTP or DNS server has multiple addresses, clients are required,
practically (many servers are behind firewalls) or, for DNS, officially
by RFC1035, to try all the IP addresses of the server, which is a form
of an applicatin layer end to end multihoming.

That DNS is an intelligent intermediate system is blessing rather than
a curse, because it enables many to many mapping between hostnames and
IP addresses, which is essensial for end to end multihoming to reduce
the number of the global routing table entries.

						Masataka Ohta


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