Subject: RE: [mobile-ip] MOBILEIP WG Minutes (56th IETF, San Francisco)

From: "Hesham Soliman (EAB)" <[email-masked]>
Date: Tue, 22 Apr 2003 19:41:06 +0200

Ed, 

  > "  There is also one idea that could be added to Mobile 
  > IPv6 at a later
  >    stage, which is to make the movement detection more 
  > explicit.  The
  >    idea is to configure the routers on each link to 
  > advertise a single
  >    global IPv6 address as the "identity" of the link in each Router
  >    Advertisement.  This can be done by defining a new 
  > Neighbor Discovery
  >    option.  Thus a Mobile Node when it receives a Router 
  > Advertisement
  >    can immediately tell whether it has moved - the global 
  > identity will
  >    be different for each link."
  > 
  > In this case, "identity of the link" will normally be 
  > identity of a single
  > router (excepting the case when a global scope anycast 
  > address is used to
  > identify a set of routers on the same link, which is one 
  > possible way to
  > implement this), but then in our MN implementation we treat 
  > a single router
  > as a virtual link anyways so same intent.
  > 

=> I'm not sure that this addresses the problem in the 
quoted paragraph above. If a link has more than one 
router and they advertise different prefixes, then
the R bit will not help. There is no requirement
that all routers on a link advertise all prefixes. Of course
they can be configured to do so, but I haven't seen
this requirement anywhere. 
Not something for this spec to fix, it's a general
issue. 

Hesham