On 24/04/12 04:21, Adrian May wrote:
Hi Simon,
In the meantime I installed ClearOS, which uses dnsmasq. Now the PCs get
served fast but my embedded boards are still not getting IPs. If I plug
these embedded boards into my 10 dollar domestic router, they get an IP
instantly. I already tried setting bootp-dynamic and dhcp-broadcast in
the config. If I grep everything under /var/log for dnsmasq, there's no
evidence that requests were even received from these boards. So I still
suspect the networking layer.
As for the boards themselves, I'm not entirely sure what they do.
They've got some kind of embedded linux. One boots into yamon where I
can only say "net init", the other into something of its own invention
where I start udhcpc.
I tried no-ping but it had no effect. I can't get my brain around your
tag system. I've just been writing things like bootp-dynamic with no
tags right in the main config file, or in the case of ClearOS, in the
dhcp config file which is referenced from the main config file. Could it
be that these settings have no effect unless I attach some tags, or put
them inside a subnet declaration?
No tags -> applies everywhere, so that's not the problem.
Do you have some combination of --interface, --listen-address and
--dhcp-except that's telling dnsmasq not to do DHCP on the network these
things are plugged into? Can you plug a laptop or something into the
same port and get a DHCP lease?
If you can narrow it down to just these embedded boards, then we'll have
to start looking at packet dumps.
Cheers,
Simon.
Adrian.
On 04/23/2012 08:01 PM, Simon Kelley wrote:
On 23/04/12 12:02, Adrian May wrote:
Hi all,
I get the same result with dnsmasq, dhcp3-server and isc, namely, that
the client has to send several DHCPDISCOVER packets before the server
finally responds after about 30 seconds. This is breaking a couple of
embedded platforms because they aren't that patient, and I have no way
of configuring that.
Why don't DHCP servers just respond to the first DHCPDISCOVER?
Especially when I made them authoritative?#
Servers allocate an address and then ping it for a few seconds just to
be sure it's not in use. That's the main delay. In dnsmasq --no-ping
will stop this behaviour. Also the client is entitled to wait around
collecting answers from more than one server before deciding which one
to use; they rarely do this and it doesn't sound like yours are.
I think I might have seen in the logs that the dhcp processes aren't
even getting the earlier packets, even though the machine is. It's as if
they get discarded by the networking layer. This is a ubuntu server
10.04 machine.
Firewall rules can affect things, but the result is rarely
intermittent. Is your network heavily loaded and dropping packets?
Cheers,
Simon.
Any ideas?
Adrian.
_______________________________________________
Dnsmasq-discuss mailing list
Dnsmasq-discuss@lists.thekelleys.org.uk
http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
_______________________________________________
Dnsmasq-discuss mailing list
Dnsmasq-discuss@lists.thekelleys.org.uk
http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
_______________________________________________
Dnsmasq-discuss mailing list
Dnsmasq-discuss@lists.thekelleys.org.uk
http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
_______________________________________________
Dnsmasq-discuss mailing list
Dnsmasq-discuss@lists.thekelleys.org.uk
http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
