RE: network controls are necessary

["Tony Hain" <alh-ietf@tndh.net>]

Tony Li wrote:
> ....
> I'm somewhat offended that you would accuse us of being 
> partisan.  

I was not trying to acuse or label anyone. My point was that we all are
bringing viewpoints based on past expierence, and they can cause
particular approaches to be declaired 'too complex' without serious
study. 

> This
> is an architectural discussion about the right engineering compromises
> to help grow the Internet.  I'm fully cognizant of what a 
> host administrator
> has to do.  I was a Unix and VMS sysadmin for USC from 1983-2000.  We
> supported over 2000 workstations and 30,000 user accounts.  
> Simplifying
> host management was a requirement then and still.

Simplifying does not always mean moving the function into the network.
In fact that approach may make the host job more complex, because the
network has limited knowledge. 

> 
> I have nothing to gain by having control in the SBR.  I no 
> longer work 
> at Cisco, so I have no interest in placing more responsibility and 
> complexity into the CPE gear.  I'm just trying to design a 
> clean architecture
> that scales.  That's what we should all be striving for.

I agree, and was not trying to acuse anyone of focusing on financial
gain. I do think we need more voices involved from host & network
administrators of end sites that are currently multi-homed. The real
trick is finding the people from that set who are willing to put time
into the IETF, and who have some understanding of the range of options
they will have with IPv6. If everyone approaches this from the
standpoint of 'this is how it is done in IPv4', we may be unnecessarily
limiting our options.

> 
> Our first job is to define an architecture, not a mechanism.  That
> architecture will be able to support some policies, not all.  

I agree we can't arbitrarily support all policies, but we appear to be
writing off a significant number of them because the mechanisms that
would allow them to fit into the target architecture are too complex. 

> We need to
> understand the bounds of the policies that can be supported by a
> particular architecture and to choose the architecture which 
> balances policy against complexity and our other design goals.
> Supporting all possible policies is not an architectural trait that
> is supported with either host or SBR policies.  The amount of possibly
> relevant information that either of them will have is far too limited
> in any rational design to begin to implement all policies.
> 
> So we have to choose.

Yes we have to choose. My concern is that the vocal participants are not
providing a balanced perspective on the cost / benefit tradeoffs. Again,
this is not to fault anyone, just raise awareness that we need more
participation from multi-homed host administrators.

Tony