Subject: RE: Proposal for site-local clean-up

From: "Hesham Soliman (EAB)" <[email-masked]>
Date: Tue, 12 Nov 2002 23:14:23 +0100

I don't really have a strong opinion one way
or the other, but I would like to make the following
observations: 

- "MUST NOTs" are there for a reason, saying MUST NOT
when it can be done and protocols don't break is not
a good idea. 

- People have shown that there are ways of using 
site-locals for single and multi-sited hosts today and 
making sure that apps don't break. We've also seen that 
this comes at a cost and complexity, but it is possible 
with today's standards. 

- Defaults for hosts and routers have been discussed
and it looks like we have some pretty straight forward
defaults to handle SLs (see Bob hinden's emails among
the other thousand emails on this). 

Personally, I don't have a big problem with the suggestion
itself, but I do not agree with it, simply because
it's a meaningless restriction. I'd rather see a 
separate BCP for this, or at least say should not and 
explain why. 

Finally, I do hope to see the addrarch RFC in DS in my 
lifetime. 

Hesham

PS: You know many designs are not perfect the first
time around and band aids are often needed later. 
In this case the problem is not that big. IMHO
changing fundamental RFCs when people are shipping 
products is worse than having a band aid for SLs.
Please, let's move on and get a BCP.
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From: Keith Moore <[email-masked]>
Date: Tue, 12 Nov 2002 18:37:23 -0500

> when it can be done and protocols don't break is not

perhaps not, but protocols DO break when we subject them to SLs.

changing those protocols is nontrivial, and they will still break
after such changes, just not as often.  (they'll also be less 
efficient)

> making sure that apps don't break. 

actually, no.  people have shown that there are ways of using SLs for some 
apps in such situations.  nobody has come up with a general solution that 
requires less than either:
- expecting all non-isolated networks to provide global addresses 
  (and having apps ignore SLs in the presence of globals), or 
- expecting apps to do their own addressing and routing.

> it's a meaningless restriction. 

I have a hard time understanding how a simple restriction that
allows apps to work is meaningless.

> In this case the problem is not that big. 

Yes, it's a simple problem to fix.  The fix is just to discourage
use of SLs except in disconnected networks.  Any other "fix" places
more burden on networks or applications or both, and this does 
create a "big" problem.

> IMHO

What you seem to favor seems more like a tourniquet than a band aid.  

Keith