intelligence in end systems [was Re: Draft of updated WG charter

[Brian E Carpenter <brc@zurich.ibm.com>]

This was discussed during the work on RFC 3582 and our goal in this
area is stated in that RFC. Please do not re-open old debates; we are
trying to make progress, not repeat previous work.

  Brian
  co-chair

Jay Ford wrote:
> 
> On Fri, 9 Jan 2004, vijay gill wrote:
> > Routing update validation should be orthogonal to the multihoming
> > solution.  Also, I am going out on a limb here and say that any
> > m-homing solution that requires end-host updates is a non-starter
> > from the get-go.
> 
> I'll go further out on that limb & say that any multi-homing solution which
> requires substantially more intelligence in end systems than is currently
> required for multi-homed IPv4 is bound to fail, even if you somehow get it
> deployed.
> 
> This is really the heart of the IPv6 scalability issue.  I've never
> understood the argument that multi-homing for IPv6 ought not be done the way
> it's done for IPv4 (single address per end system, multi-path routing) on the
> basis that the network can't tolerate the increase in routing table
> size/complexity.  My objection is that the alternative (shoving the
> complexity to the end systems) is much worse because:
>    o  as evidenced by worm attacks..., the end systems are the worst managed
>       pieces in the whole puzzle run by users who don't (& I'd say shouldn't
>       be expected to) understand the workings of the network;  predicating
>       routing-type functionality on that platform is asking for trouble
>    o  there are at least 3 (4? 5?) orders of magnitude more end systems than
>       there are routers, so embedding significant pieces of networking
>       functionality in end systems greatly increases the likelihood of
>       trouble & even more greatly decreases the chance of consistent
>       operation over time
> 
> Consider the current difficulty in deploying changes to other technologies
> due to system-level inertia (e.g., ASM->SSM for multicast).  Those are
> relatively upper-level things which for the most part don't affect the basic
> ability to get packets delivered.  Moving routing-type burden to the end
> systems creates such inertia for basic packet delivery, making the network as
> a whole even less upgradable than it is now.
> 
> I advocate keeping the end systems as simple as possible & dealing with the
> routing support required to make multi-homing work close to the way it works
> for IPv4.
> 
> ________________________________________________________________________
> Jay Ford, Network Engineering Group, Information Technology Services
> University of Iowa, Iowa City, IA 52242
> email: jay-ford@uiowa.edu, phone: 319-335-5555, fax: 319-335-2951

-- 
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Brian E Carpenter 
Distinguished Engineer, Internet Standards & Technology, IBM 

NEW ADDRESS <brc@zurich.ibm.com> PLEASE UPDATE ADDRESS BOOK