>>>>> On Tue, 18 Dec 2001 07:34:49 +0100 (CET),
>>>>> Erik Nordmark <[EMAIL PROTECTED]> said:
>> Okay with me, too. I just tried to make the document clear in the 03
>> draft, but in fact I don't see practical usage of receiving the
>> optional information on TCP sockets. If we can reach a consensus of
>> leaving it unspecified (by removing the text), it's just fine.
> At one level I don't have a problem with removing the 02 and 03 behavior since
> no TCP applications use this.
> However, I wonder what we would do if a TCP application comes around and
> wants to either restrict the extension headers used on the receive side and/or
> be aware of what is used.
> Perhaps this is something we can only speculate given that no such
> applications exist.
As for the restriction, we cannot take the same approach as UDP and
raw IPv6, i.e., making a decision by receiving the extension headers
at the application side. So, the restriction mechanism should be a
kind of packet filtering at L3 or L4, and applications can only
control the filter policy by some other APIs that are totally
different from the ones we're talking about.
As for the awareness of what extension headers are used, the problem
is that we don't have concrete usage of it. Additionally, even if we
provided a way, it would not be very useful because we'd not be able
to follow changes on the extension headers (perfectly). Meanwhile, we
have already had system-dependent interfaces to grab the headers,
e.g. BPF or DLPI. An application could use such interfaces if it
strongly wanted to get the extension headers (and other optional info)
for some very special purposes, though such interfaces may require
additional privilege.
If we can reach consensus on removing the current (and previous) text
and want to make some comments on this, I'd propose to put
considerations like above into the next revision of the draft.
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]
--------------------------------------------------------------------
