>>>>> On Sat, 17 Jun 2000 21:11:56 +0200,
>>>>> Francis Dupont <[EMAIL PROTECTED]> said:
> In your previous mail you wrote (after reformatting into text):
> 3) When multicast addresses are stored in a sockaddr_in6, how is the
> scope id field Interpreted?
> => I believe it should be an interface index because it is the way
> it works today (or before scope id introduction if you prefer :-):
It would work, but I'd rather use the same semantics for both unicast
and multicast. That is, sin6_scope_id should just specify a zone ID,
not an interface, even for a multicast address.
> IPV6_MULTICAST_IF & IPV6_JOIN_GROUP deal with interfaces, not with
> interface sets.
Yes, these are interfaces oriented. But, it sin6_scope_id is not, at
least in my understanding of scope architecture. Specifying a
particular interface by the sin6_scope_id field seems to me
overspecification, if the scope is wider than interface (i.e. link or
broader scopes).
Also, if the sin6_scope_id field specified a single interface for a
multicast address, we couldn't do
- bind a socket to a site-local multicast address with an appropriate
sin6_scope_id,
- set IPV6_JOIN_GROUP for that address on multiple interfaces (of the
specified scope zone), and then
- receive packets that arrive on the specified interfaces via the
socket
I don't think this is really a practical example, but IMO, this type
of behavior is allowed in IPv4 (i.e. bind once, and call
IP_ADD_MEMBERSHIP multiple times to receive packets to the group on
multiple interfaces), and should be allowed in IPv6 as well.
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]
--------------------------------------------------------------------
