<html><head></head><body><div style="font-family: Verdana;font-size: 12.0px;"><div>That was indeed the problem. Thanks a lot!</div>
<div> </div>
<div>it was a rule in the PREROUTING chain of the raw table:</div>
<div>rpfilter --invert -j DROP </div>
<div>
<div>that caused messages incoming from clients to be dropped.</div>
<div> </div>
<div>It is easy to modify the rule to allow dhcp traffic through, so problem solved.</div>
<div> </div>
<div>I have another question however about this:</div>
<div>> ISC's dhcp server uses a lower-level network model than dnsmasq, and can work despite iptables rules to the contrary.</div>
<div>How can an app bypass the kernel firewall? Can you please suggest a reference for me to understand better? </div>
<div> </div>
<div>A.</div>
<div name="quote" style="margin:10px 5px 5px 10px; padding: 10px 0 10px 10px; border-left:2px solid #C3D9E5; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;">
<div style="margin:0 0 10px 0;"><b>Sent:</b> Wednesday, January 04, 2017 at 3:15 AM<br/>
<b>From:</b> "Kurt H Maier" <khm@sciops.net><br/>
<b>To:</b> "Archimede Pitagorico" <archimede.pitagorico@mail.com><br/>
<b>Cc:</b> dnsmasq-discuss@lists.thekelleys.org.uk<br/>
<b>Subject:</b> Re: [Dnsmasq-discuss] Problem using dnsmasq as dhcp</div>
<div name="quoted-content">On Mon, Jan 02, 2017 at 05:50:42AM +0100, Archimede Pitagorico wrote:<br/>
> I am trying to migrate from dhcpd to dnsmasq for my home network, without<br/>
> much luck.<br/>
<br/>
Make sure you don't have any iptables rules in place that would<br/>
interfere with dnsmasq. ISC's dhcp server uses a lower-level network<br/>
model than dnsmasq, and can work despite iptables rules to the contrary.<br/>
Check for rules that are dropping packets with sources or destinations<br/>
like 0.0.0.0 or 255.255.255.255.<br/>
<br/>
<br/>
khm</div>
</div>
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