>>>>> On Mon, 08 Apr 2002 23:56:32 +0900,
>>>>> JINMEI Tatuya <[EMAIL PROTECTED]> said:
>> Well, i've just seen bad and worse ip multicast applications over the
>> last 10 years, programmers have been ignorant about the issues at hand
>> and people who deploy the applications have been ignorant about the
>> network issues they cause.
> Out of curiosity, do you have concrete examples of the bad
> applications? I tend to agree with you, but I'm still not fully
> convinced that application programmers are that silly and we need to
> add the complicated intelligence to the kernel.
I've got an example from a private message, and I now agree that we
need some changes on the current API spec.
Considering the tradeoff between the advantage of safe API
specification and the disadvantage of the loss of compatibility and/or
the complexity of the additional API knobs, I'd like to propose the
following approach:
allow IPV6_USE_MIN_MTU 3 arguments, -1, 0, and 1. the semantics of
the 3 values are as follows:
-1: if the destination is unicast, regard the path MTU and perform
path MTU discovery if necessary. if the destination is
multicast, fragment the packet at the minimum MTU (and disable
path MTU discovery as a result)
***This is the default value of the option, including the case
where the application does not explicitly specify this option***
0: always regard the path MTU, regardless of the destination
(unicast or multicast).
1: always fragment packets at the minimum MTU, regardless of the
destination.
This way the default behavior will be optimal while keeping
compatibility to existing implementations that use IPV6_USE_MIN_MTU
and avoiding additional socket options.
This may still be regarded as an ad-hoc solution, but I believe this
is practically the best way.
Is this change acceptable?
JINMEI, Tatuya
Communication Platform Lab.
Corporate R&D Center, Toshiba Corp.
[EMAIL PROTECTED]
--------------------------------------------------------------------
IETF IPng Working Group Mailing List
IPng Home Page: http://playground.sun.com/ipng
FTP archive: ftp://playground.sun.com/pub/ipng
Direct all administrative requests to [EMAIL PROTECTED]
--------------------------------------------------------------------
