[Dnsmasq-discuss] [PATCH v2] DHCPv6: Honor assigning IPv6 address based on MAC address

[Pali Rohár]

On Thursday 23 July 2020 13:11:36 Move On wrote:
> On Thu, Jul 23, 2020 at 10:35:45AM +0200, Pali Rohár wrote:
> > So finally something relevant to this patch...
>  
> Cheer   \o/
> 
> > On Wednesday 22 July 2020 23:48:19 Petr Menšík wrote:
> > > On 7/22/20 3:44 PM, Pali Rohár wrote:
> > > > I do not see any benefit why to complicate things just because "IPv6
> > > > addresses are many". I do not see nothing wrong on simple setup where
> > > > device has one IPv6 address assigned by DHCPv6 server.
> > > I think you are requesting breaking of DHCP definition RFCs. I see
> > > nothing wrong with IPv6 assigned to MAC address. I think it is wrong, if
> > > there are existing leases for the same address with different IAID.
> > 
> > The whole point of this patch is to make MAC --> IPv6 address assigning
> > working. It means that IPv6 address must be leased to MAC address if
> > assigning is based on MAC address and not on DUID/IAID.
> > 
> > If user set in configure file that for MAC address AB:CD:EF:AB:CD:EF
> > must be assigned IPv6 address FD::1 then user would expect that host
> > with address AB:CD:EF:AB:CD:EF would get IPv6 address FD::1.
> > 
> > Why host get different address, then why such option is even provided?
> > 
> > User already express by this configuration that he is interested in such
> > setup even if it does not have to be compliant with standards.
> > 
> > Some people are saying that assigning IPv6 address based on MAC address
> > is already violation of DHCPv6 RFC.
> > 
> > Also dnsmasq provides support for leasing one IPv4 address to more MAC
> > addresses. This is often used when computer has both ethernet and wifi
> > interfaces and only one is used at the same time. dnsmasq then lease
> > IPv4 address to the last MAC address which asked for it. This feature
> > also violates DHCPv4 standard, but it is there as it is useful for lot
> > of people.
> > 
> > So why should be similar useful feature problematic for IPv6 when it is
> > already provided for IPv4 in dnsmasq?
> > 
> > 
> > Anyway, if violation of DHCPv6 RFC standard with this setup of leasing
> > IPv6 address to MAC address statically is problematic, what about adding
> > a new option which enables this behavior?
> > 
> 
> Provide PATCH v3  and see what happens

So, this is the only thing which needs to be fixed and after patch would be merged?

-- 
Pali Rohár
pali.rohar at gmail.com