[Dnsmasq-discuss] DHCPv6 Server not respecting lease time setting

[Simon Kelley]

On 31/07/13 23:06, Jonathan Fabian wrote:
> Hi,
>
> I'm seeing some strange behavior between my mac and dnsmasq (running on
> arch linux arm) when getting assigned an IPv6 address. Specifically, I have
> the DHCPv6 set to give out a 12 hour lease time: dhcp-range=a:b:c::1,
> a:b:c::ff, 64, 12h, but it will only give the mac a 2 min lease time (as a
> side note, I have also tried setting a dhcp host option specifically for
> macs duid and it ignores those lease time values as well). The lease time
> setting works fine with the windows machines on the same network.
>
> Looking at the network packets, I see the mac solicit the dhcp server, the
> dhcp server replies with an advertisement message offering an ip address
> with a valid and preferred lifetime of 43200, then the mac replies with a
> request for the advertised ip address with the valid and preferred
> lifetimes set to 0 (which looking at rfc3315 should be treated as no
> preference), dnsmasq then sends back a reply with the address but the valid
> and preferred lifetimes only set to 120 (the min time allowed)!
>
> The only difference I can see with the windows machines is that when a
> windows machine sends the request message they copy the preferred and valid
> lifetimes of 43200 from the advertise message.
>
> Maybe I'm wrong, but it seems that dnsmasq should always be ignoring the 0
> when sent, and only treating the valid and preferred lifetimes from the
> client as a request at best. It seems, however, to be treating them in a
> manner that overrides the explicitly configured setting in its config
> files. Can anyone shed some light on this behavior?
>
> Thanks,
> Jonathan
>

I just pushed a patch into the git repo that should fix this.


Cheers,

Simon.