You don't need to go through crontabs and such; the network hardware should do it all for you.
Your router should be set to do NAT'ing to your internal local network; most routers made in the last 10 years have the capability to talk to the dynamic DNS update services when they discover an IP change on the outside interface.
You register with DYNDNS or another service with a fixed domain name, and use the DYNAMIC DNS as your authoritative DNS for the purposes of establishing your presence on the network.
Assuming you have port forwarding set up properly, your inbound traffic on the IAX port gets forwarded to the NAT IP address of your asterisk box, and if you're enabling SSH to the outside world, then you forward that port also, on the router inbound. If all you have behind the router is your asterisk box, I'd not enable any other inbound ports. You're only inviting in the scan bots from the pacific and eastern european malcontents.
Allstarlink will recognize the changing IP as your server phones home occasionally. So, repeaters outside of your own will be able to connect.
Your addresses behind your router never change; I suggest using 192.168.1.x as the network, 255.255.255.0 (or 0xffffff00) as your netmask, and whatever the internal port on the router (is usually the x.x.x.1 address) as your gateway.
If you have multiple repeaters on the same asterisk instance behind your NAT'd router/firewall, then you have to make the appropriate entries in your config files so you can register properly on the internal network.
If I've left anything out...I'm sure others will chime in.
(This is being done on a whole number of systems I know of, successfully, for many years. I don't do it this way, since I signed up for business class service with fixed IPs. The business class service costs a bit more, but the QoS is higher, and business service has priority over the consumer internet in the Philly area. And since I run web servers for various interests and organizations, it's not allowed on consumer class service...so, had to go with the business class and have not been disappointed. Only drop out I had was post Sandy (but, then, the entire region was out for almost a week electrical/phone/cable/internet).)
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On 10/20/2015 5:27 PM, Loren Tedford wrote:
My isp is still changing my ip about every 2 to 3 hours i managed to get
a dyndns type application to run through linux so i have constant ssh
access to the machine however my script i put in crontab -e is not
working to grab the new ip and email it nor is it restarting the server
if the ip had changed.. I am now trying to figure out if asterisk needs
to update info to allstar and how to do this..