On Wed, Jan 15, 2014 at 10:06 AM, Daniel-Constantin Mierla &lt;miconda(a)gmail.com&gt; wrote: On that OPTIONS ping topic, I hit a bug recently with Kamailio 3.3 running on 2 ethernet interfaces (one public, one private). It seems the OPTIONS ping has always an SRC_IP of the first listen interface defined in kamailio.cfg, while the machines on both sides expect an SRC_IP which is in their range. I had to fix it with some iptables glue to rewrite the SRC_IP with: iptables -t nat -A POSTROUTING -p udp --dport 5060 -s my_public_ip/32 -d private_ip_of_the_destination/32 -j SNAT --to-source my_private_ip/32 Any idea if this could be fixed within kamailio? Best, -- Benjamin Henrion <bhenrion at ffii.org> FFII Brussels - +32-484-566109 - +32-2-4148403 "In July 2005, after several failed attempts to legalise software patents in Europe, the patent establishment changed its strategy. Instead of explicitly seeking to sanction the patentability of software, they are now seeking to create a central European patent court, which would establish and enforce patentability rules in their favor, without any possibility of correction by competing courts or democratically elected legislators."