I am just curious about what are the technical differences between a link-local address and a subnet-local address.
I agree with Dave that, doing a DAD for "link-local" type of post-fix address is a unnecessary restriction. 1. There might be global addresss manually configured with the same post-fix but with different pre-fix as the link-local address of a node. What would HA do if a node like that moves into its territory ? 2. For 64-bit post-fix it would render 2**64 perfectly good addresses useless. Subrata -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf Of Dave Thaler Sent: Friday, May 31, 2002 10:59 AM To: Charles E. Perkins; Richard Draves Cc: [EMAIL PROTECTED]; IPng Working Group Subject: [mobile-ip] RE: RFC 2462 DAD optimization As mentioned in email I sent a week or two back, this is related to the issue of whether a link-local address has to be unique across an entire subnet, not just a link. Today it's defined as a "link-local" not a "subnet-local" address. This means that it is not guaranteed to be unique across a subnet. Manually configured global addresses don't need to require rights to the corresponding link-local address since a) it's not necessary as they don't use the link-local address, b) it's not sufficient since they need to be unique across the subnet, not just the link. So unless you're proposing we redefine "link-local" addresses as "subnet-local" addresses (which would at least be a consistent argument, albeit a change to the architecture), then what you suggest does not seem to me to be the right solution. -Dave > -----Original Message----- > From: Charles E. Perkins [mailto:[EMAIL PROTECTED]] > Sent: Friday, May 31, 2002 10:45 AM > To: Richard Draves > Cc: [EMAIL PROTECTED]; IPng Working Group > Subject: Re: RFC 2462 DAD optimization > > > Hello Richard, > > Even manually configured global addresses should be required > to acquire rights to the corresponding link-local address. Why not? > > Regards, > Charlie P. > > > Richard Draves wrote: > > > > I disagree. I think the problem is in the RFC 2462 optimization. The RFC > > 2462 optimization also can fail with manually-configured addresses - > > it's not just a problem with RFC 3041 temporary addresses. > > > > I'm curious about the implementation status. I know the Windows > > implementation does not implement the RFC 2462 optimization - it > > performs DAD on every address independently. What about other > > implementations? > > > > Rich > > > > > -----Original Message----- > > > From: Charles E. Perkins [mailto:[EMAIL PROTECTED]] > > > Sent: Friday, May 31, 2002 10:03 AM > > > To: Hesham Soliman (ERA) > > > Cc: '[EMAIL PROTECTED] '; 'IPng Working Group ' > > > Subject: Re: [mobile-ip] Issue #23 and Issue #30 > > > > > > > > > > > > Hello Hesham, > > > > > > "Hesham Soliman (ERA)" wrote: > > > > > > > => RFC 2462 makes an optimisation (not a good > > > > one IMHO) that if a node does DAD on link-local > > > > addresses, it 'owns the interface id' for any other > > > > address with any scope. > > > > > > I think this is a good idea. > > > > > > > RFC3041 says that a node can generate a new iid > > > > and does DAD for _that_ address which uses the > > > > new iid. Since this is typically not a link local > > > > address, you could get a conflict if the HA > > > > does not defend all addresses. > > > > > > The problem is that RFC 3041 should require any > > > such node to first acquire rights to the link-local > > > address. I hope that is viewed as an omission, and > > > one which can be quickly repaired. > > > > > > Regards, > > > Charlie P. > -------------------------------------------------------------------- > 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] > -------------------------------------------------------------------- -------------------------------------------------------------------- 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] --------------------------------------------------------------------
