Adding second listening port to Asterisk
2021-10-07 by: lMike
To add a second listening port to an Asterisk system you have to do some tricks, because Asterisk will only listen to 1 port. IPTABLES to the rescue. You will want "iptables-persistent" if you don't have it. It's the last step because you will want it to save the rules you just made so they survive reboot. If using other iptables managers, you will want to do it their way.
On a bare/fresh Asterisk system running port 5060 or 5061:#flush existing nat rules iptables -t nat -F #redirect 55060 to 5060 iptables -t nat -A PREROUTING -i eth0 -p udp --dport 55060 -j REDIRECT --to-ports 5060 iptables -t nat -A PREROUTING -i eth0 -p udp --dport 55061 -j REDIRECT --to-ports 5061 #show rules iptables -L -t nat -n #install iptables-persistent apt install iptables-persistent #to save and update rules anytime. iptables-save >/etc/iptables/rules.v4 #reboot and test.