[Dnsmasq-discuss] DHCPv6 - network booting 'address in use'

[Geert Stappers]

On Tue, Sep 14, 2021 at 04:58:10PM +0200, Harald Jensas wrote:
> Hi,
> 
> We are seeing an issue whit network booting over DHCPv6 is failing.
> The UEFI firmware is starting two DHCPv6 transactions, with separate IAID's.
> Initially one transactions succeeds, while the other transaction fails
> because the same address (fd42::200) is advertised.
> 
> On error, the client tries to recover by restarting the transaction with a
> new SOLICIT, the second address (fd42::201) in the host's range
> [fd42::200/126] is advertised by dnsmasq.
> 
> Despite requesting the second address, the dnsmasq is refusing the lease:
> dnsmasq-dhcp: 14744450 nest size: 16 option: 13 status  1 address in use
> dnsmasq-dhcp: 14744450 sent size: 24 option: 13 status  2 no addresses available

Why the   /126?