[Dnsmasq-discuss] IP assigning for wrong network

Tamas Papp tompos at martos.bme.hu
Sat Feb 22 22:58:09 UTC 2014


On 02/20/2014 06:12 PM, Simon Kelley wrote:
> On 19/02/14 23:03, Tamas Papp wrote:
>> hi All,
>>
>>
>> Feb 19 23:49:48 workhorse dnsmasq-dhcp[6678]: DHCPINFORM(eth-clients)
>> 10.0.1.233 70:54:d2:1b:18:59
>> Feb 19 23:49:48 workhorse dnsmasq-dhcp[6678]: DHCPACK(eth-clients)
>> 10.0.1.233 70:54:d2:1b:18:59 vweiszfeiler-pc
>> Feb 19 23:49:51 workhorse dnsmasq-dhcp[6678]: DHCPINFORM(eth-clients)
>> 10.0.1.233 70:54:d2:1b:18:59
>> Feb 19 23:49:51 workhorse dnsmasq-dhcp[6678]: DHCPACK(eth-clients)
>> 10.0.1.233 70:54:d2:1b:18:59 vweiszfeiler-pc
>>
>
> So, in that log fragment there's no assignment going on. The client is
> asking for configuration information, and dnsmasq is sending it. The
> only thing dnsmasq could do differently is to ignore the DHCPINFORM
> when the IP address the client sends is not on the network that the
> client appears to be on, but that bfreaks other, useful use-cases fro
> DHCPINFORM.

What is the reason they do this?
It doesn't make sense to me. I mean if they are just chatting, but don't
do anything, then no reason. In my logic (just human logic, I don't know
rfc:) the dhcp should send DHCPNAK to let the client know about the
situation.
What else could be the goal of DHCPINFORM? Maybe informing the server,
that the client is using that IP address?

> If/when the client does DHCPREQUEST and attempts to renew the lease,
> dnsmasq should respond with with DHCPNAK and then the client will move
> IP addresses. When that happens depends on when the lease expires.

I see, thanks.

tamas



More information about the Dnsmasq-discuss mailing list