Date: Tue, 05 Sep 2000 09:02:52 -0600 From: Brad Huntting <huntting@hunkular.glarp.com> To: itojun@iijlab.net Cc: bugs@freebsd.org, huntting@glarp.com, Hajimu UMEMOTO <ume@mahoroba.org>, core@kame.net Subject: Re: kern/21016: IPV6_JOIN_GROUP doesnt work for mapped IPv4 multicast addresses Message-ID: <200009051502.JAA26962@hunkular.glarp.com> In-Reply-To: Your message of "Tue, 05 Sep 2000 09:29:42 %2B0900." <8621.968113782@coconut.itojun.org>
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>>> this is a feature. IPv4 mapped address on AF_INET6 socket is just >>> to help porting basic IPv4 apps at ease. to manipulate IPv4 traffic >>> in detail (including TOS/TTL, or multicast), you must use AF_INET >>> socket. >>Section 3.7 of draft-ietf-ipngwg-rfc2553bis-00.txt does not aggre. >>V4 mapped addresses are clearly intended to allow "basic" v6 apps >>to interoperate with legacy v4 apps w/o duplicating code. And >>"basic" in this case most definitly includes multicast. > where did you get the impression for the last sentence? > from my understanding, multicast is outside of scope (and I'm very > convinced about it) > the more you try to use IPv4 mapped address in wider scope, the system > gets more messy. "basic" as in draft-ietf-ipngwg-rfc2553bis-00.txt "Basic Socket Interface Extensions for IPv6". But more specifically, the paragraph 4 of section 2: - Where possible, applications should be able to use this API to interoperate with both IPv6 and IPv4 hosts. Applications should not need to know which type of host they are communicating with. [....] Because of the importance of providing IPv4 compatibility in the API, these extensions are explicitly designed to operate on machines that provide complete support for both IPv4 and IPv6. A subset of this API could probably be designed for operation on systems that support only IPv6. However, this is not addressed in this memo. And since section 5.2 of this draft clearly lays out the multicast socket options, it would seem that multicast is "basic", and that one should be able to use this multicast API on mapped addresses. Besides, it makes sense to include multicast. Otherwise each application will need seperate code to deal with v4 and v6 multicast addresses. And this is exactly the problem that mapped v4 addresses are supposed to solve. >>Is KAME planning on fixing this anytime soon? > I don't think so. I can't speak for other KAME guys. It sounds like this is worth asking the ipng group at any rate. brad To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-bugs" in the body of the message
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