Re: [v6ops] Please review the No IPv4 draft

[Ray Hunter <[e-mail]>]

> Ted Lemon <mailto:[e-mail]>
> 15 April 2014 05:17
>
> The network is mismanaged or under attack. Fix it.
>
See Homenet Architecture 3.2.2.2.  B: Two ISPs, Two CERs, Shared subnet. 
http://tools.ietf.org/html/draft-ietf-homenet-arch-13#page-18

What when one ISP says "No IPv4 Service" whilst the other ISP says "Yes 
IPv4, and here's your address"?

This is NOT a misconfiguration IMHO, but a weakness in the assumptions 
lying behind this draft i.e. that all routers on a link are managed by 
one self-consistent management entity for both IPv6 and IPv4.
> Ray Hunter <mailto:[e-mail]>
> 14 April 2014 22:21
>
>
>
>
> That we are discussing turning off IPv4 in both RA and DHCPv6 just 
> highlights to me how ridiculous host configuration has become.
>
> To me this proposal just introduces all sorts of horrible race 
> conditions and inconsistencies, and I'm not convinced it's any better 
> than just configuring up IPv4 via DHCPv4 with either a self assigned 
> address or an RFC 1918 address and saying nothing about remote 
> connectivity (given that most OSes already have IPv4 detection 
> mechanisms in place to work out whether they are on a corporate 
> network with proxies or the Internet or on an isolated island or 
> whatever.)
>
> e.g. what does a host do if RA says turn off IPv4, but DHCPv4 replies 
> either before or after a host receives that RA advertisement?
> Does the host have to then disable IPv4 once it is already up? For how 
> long?
>
> What if DHCPv6 and RA are not consistent (given they may not even be 
> the same router or device responding)?
>
> What if one router is IPv4 only and the other IPv6 only? And they're 
> from 2 different ISP providers connected to a common L2 LAN? That's a 
> perfectly valid configuration in my opinion.
>
> Can an absence of "turn off IPv4" message be taken as a "turn on IPv4"?
>
> How would this be implemented consistently given RA is generally ICMP 
> (kernel space) and DHCPv6 user space (daemon)?
>
> Given the O and M bit saga, what makes anyone think that this 
> additional signalling will be any better?
>
> Why would any end host trust this message?
>
> IMHO the place to turn off or signal limited IPv4 connectivity is in 
> DHCPv4 (if we ever even attempt to do that).
>
> ------------------------------------------------------------------------


-- 
Regards,
RayH