[Dnsmasq-discuss] Cannot obtain IP address from dnsmasq

[Albert ARIBAUD]

Hi Matwey,

Le Fri, 24 Jun 2016 19:30:04 +0300
"Matwey V. Kornilov" <matwey.kornilov at gmail.com> a écrit:

> 2016-06-24 19:19 GMT+03:00 Albert ARIBAUD <albert.aribaud at free.fr>:
> > Hi Matwey,
> >
> > Le Fri, 24 Jun 2016 12:10:53 +0300
> > "Matwey V. Kornilov" <matwey.kornilov at gmail.com> a écrit:
> >  
> >> Hello,
> >>
> >> I am running dnsmasq-2.71 and experiencing the following issue.
> >>
> >> I have network interface eth3 with 10.3.0.1/24 address assigned to
> >> it. I want dnsmasq instance to supply everyone on eth3 L2-segment
> >> with IP address from 10.3.0.1/24 subnet. I don't want DHCP be
> >> running on other interfaces where it can interfere others.
> >>
> >> The issue is the following, HP commutator can not obtain address.
> >>
> >> 12:03:01.609174 IP 192.168.1.1.68 > 255.255.255.255.67: BOOTP/DHCP,
> >> Request from 40:a8:f0:6f:64:40, length 256
> >> 12:03:23.952477 IP 192.168.1.1.68 > 255.255.255.255.67: BOOTP/DHCP,
> >> Request from 40:a8:f0:6f:64:40, length 256
> >>
> >> At the same time, other devises obtain address successfully:
> >>
> >> 12:03:45.311101 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP,
> >> Request from 44:aa:e8:00:0c:4e, length 249
> >> 12:03:45.313634 IP 10.3.0.1.67 > 255.255.255.255.68: BOOTP/DHCP,
> >> Reply, length 300
> >> 12:03:45.340273 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP,
> >> Request from 44:aa:e8:00:0c:4e, length 256
> >> 12:03:45.371271 IP 10.3.0.1.67 > 255.255.255.255.68: BOOTP/DHCP,
> >> Reply, length 300
> >> 12:03:45.395392 IP 10.3.0.33.1025 > 239.255.255.250.1900: UDP,
> >> length 320 12:03:46.884261 IP 0.0.0.0.68 > 255.255.255.255.67:
> >> BOOTP/DHCP, Request from 44:aa:e8:00:0c:46, length 249
> >> 12:03:46.885707 IP 10.3.0.1.67 > 255.255.255.255.68: BOOTP/DHCP,
> >> Reply, length 300
> >> 12:03:46.911271 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP,
> >> Request from 44:aa:e8:00:0c:46, length 256
> >> 12:03:46.945596 IP 10.3.0.1.67 > 255.255.255.255.68: BOOTP/DHCP,
> >> Reply, length 300
> >> 12:03:46.968662 IP 10.3.0.32.1025 > 239.255.255.250.1900: UDP,
> >> length 320 12:03:50.390213 IP 10.3.0.33.1025 >
> >> 239.255.255.250.1900: UDP, length 320
> >>
> >> I suppose, that the issue here is that HP's source address is
> >> 192.168.1.1, how could I configure dnsmasq to overcome this
> >> issue?  
> >
> > The above is a tcpdump log. What does dnsmaq itself log? Think of
> > adding the log-dhcp option to the dnsmasq config file beforehand.
> >  
> 
> Nothing about 192.168.1.1 in log-dhcp, unfortunately.

Not a dnsmasq issue, then: if the request from 192.168.1.1 never
reaches dnsmasq, it's either dnsmasq not listening on the right
interface or a network issue. Since requests from others on the
same physical network segment are seen, dnsmasq is listening on the
right interface. Therefore, it is a network issue.

Amicalement,
-- 
Albert.