Consensus on MHAP/v6 Multi-homing

[Cameron Gray]

Jeroen Massar wrote:
> If you s/MHAP/shim6/ (MHAP proposal does not really exist any more) and
> indeed that is what it is. Basically a double NAT with public, globally
> unique, address space on both sides of the NAT, which takes care of the
> problem with the current RFC1918+NAT problem, the biggest of which is
> not the NAT it self but the non-uniqueness of the addresses. The double
> NAT takes care that apps can still use the public address inside the
> protocol, eg as with ftp or h323 and it won't be hurt by the shim.

OK, I wasn't looking at specific application compatibility yet, simply 
loosing the Multi-Path benefits we have with the current IPv4 consensus.

> Most likely shim6 will depend on some sort of directory and this
> directory will not be able to live easily inside a shim area.
> 
> Fun part is that people will most likely want rapid updates for their
> shim6-mappings, at a certain point one will then simply have an overlay
> BGP network with all the routes in it too. One can drop the ASPATH
> partially then though, one only needs it to check for loops.

Sorry, I don't follow the overlay part... SHIM6 with a directory would 
cause a lookup dictating where each "real" address should be pointed 
now, but as you say updates to this must be instant and automatic.

Who gets to run these, ICANN? RIPE/ARIN/APNIC/AFNIC, et al.?  The ISPs 
I'm worried about won't accept that kind of encroachment onto their 
routing policy.  The What-Ifs are pretty much endless if they are not in 
control of that critical part of the new infrastructure.

I would see that the border for ASx would have to network xxxx::xxxx/48 
both ranges, but only one would be accepted?!?

> The only reason for 'allowing' upto /48's would be that if these would
> be "PI IPv6 blocks" that they at least do not consume that much address
> space. For the rest there is not a real reason for a /32 or a /48.
> 
> Most ISP's actually allow /48's to come through as can be verified
> easily by looking at GRH.

Example; I'm working with a small-mid sized hosting provider; not large 
enough to even contemplate becoming an LIR for a /32 v6 assignment and 
definately not going to issue 200 /48s in 2 years.

We've had UK6X deny announcement to the backbone as its longer than a 
/32.  As far as they are concerned either a) they must get a /32 and 
flaunt RIPE NCC policies or b) be allowed to multi home on the /48 they 
can get from one upstream.  If neither of these options prove fruitful 
they will simply ignore IPv6 because it's a step backwards.

If PI for IPv6 cannot be replicated takeup will be majorly hampered in 
my opinion as many smaller ISPs will lose what they consider their 
multihoming option.
-- 

Best regards,

Cameron Gray
Director, Netegral Limited
www.netegral.co.uk | cgray at netegral.co.uk
0871 277 NTGL (6845)