Re: [v6ops] IPv4 trajectory

[Alexandru Petrescu <[e-mail]>]

Sorry to insist on this, just as side note.

Le 01/04/2015 19:54, Bjoern A. Zeeb a écrit :
>> On 01 Apr 2015, at 14:07 , Alexandru Petrescu
>> <[e-mail]> wrote:
>>
>> It is customary to see current computers having both an IPv6 stack
>> and an IPv4 stack on them.  But some computers only have IPv4,
>> whereas the rest have IPv4 and IPv6 stacks.  There are no
>> computers (to my knowledge) which have only IPv6 stacks.
>
> One of my desktop systems does (not have IPv4 support anymore;

In general I can agree with you, in a sense where maybe a computer is
not reachable on IPv4 from another computer; maybe part of IPv4 support
is no more there.

> and to my knowledge you can just disable it on Windows as well,

Right - uncheck the IPv4 box, and check IPv6 on a computer Windows 7's
"Properties" of the network interface - it works.

But, after this, one can still ping 127.0.0.1, the routing table
still contains pure IPv4 entries, the domain name (which only exists in
IPv4) is still showing in ipconfig /all, the computer is still
receiving TCP and TLSv1 re-transmissions from its earlier connections.
Worse, the IPv4-only applications report errors which are not
explicitely telling there is no such address family.  I guess even netsh
interface ipv4 add address will work ok.

(compared to an IPv4-only computer: routing table does not show anything
making think IPv6, etc.)

I guess unchecking the IPv4 box simply removes IPv4 addresses from
interfaces and stops the DHCP client, maybe puts the interface down; but
it will not remove the IPv4 stack from the kernel, will not ARP inform
the router it has no more IPv4, will not recompile the apps to remove
the IPv4-only socket interfaces, will not forbid adding manually IPv4
addresses.

> so it’s not a big deal anymore).

I beg to differ, as I see it this is still far away from an ideal where
only IPv6 were present in the computer.

Alex


>
> — Bjoern A. Zeeb                                  Charles Haddon
> Spurgeon: "Friendship is one of the sweetest joys of life.  Many
> might have failed beneath the bitterness of their trial  had they
> not found a friend."
>
>
>