Re: administrivia (on avoiding injury)

[Francis Dupont <Francis.Dupont@enst-bretagne.fr>]

 In your previous mail you wrote:

   Before you implement, please answer these three questions:
   
   | > Personally, I think it's reasonable to require a host change to switch to
   | > another prefix when there is link failure. 
   
                   World----ISPZ
                     |       |
                   ISPA     ISPB
                       \   /
                       site
                         |
                       host
   
   How does host detect a link failure between ISPB and ISPZ?
   How does host detect a link failure between ISPZ and World?

=> routing protocols (ie. a suitable BGP setup)...

   When host detects either of these failures, how does it adapt
   such that there is no lost connectivity to what can still be 
   reached through site's _still operating_ connection to ISPB?
   
=> the basic idea (already published/discussed) is to use router
renumbering (router-router) and autoconfiguration (router-host)
in order to spread the information (typically reduce the preferred
lifetimes of B prefixes to zero which does exactly what one wants)
inside the site. I don't know if there is running code implementing
this but on the paper (:-) this is no hard.

Regards

Francis.Dupont@enst-bretagne.fr

PS: the other way (World to host) is a bit harder if addresses in
B prefixes no more work: DNS cannot be updated for short-term...