Dynamic DNS

GOLDF1NG3R · 11-20-2001, 04:40 AM

I currently have a cable modem which is assigned a dynamic IP address via DHCP from my service provider.

I have set up an account with DynDns.org which allows me to update the dns record for my domain via a small python script.

I am currently running this script via cron but wish to only run it when I am assigned a new IP address.

Could someone please point me in the right direction as to what is run when an IP address is obtained.

Cheers,

Chris

GOLDF1NG3R · 11-20-2001, 04:45 AM

I should have RTFM!

just found the following in the dhcpcd man page:

/etc/dhcpc/dhcpcd-<interface>.exe
file which dhcpcd will try to execute whenever it
detects a change in IP address.

finegan · 11-20-2001, 06:42 PM

Poke around the man pages for dhcpcd some more. I know there's a flag or an argument that will make the client request the same IP from the ISP. If you've got a constant connection (or more or less depending on power outages or the cat chewing on the cable), you can pretty much trick your isp into giving you a static and avoid dealing with the dynamicDNS services.

Luck,

Finegan

b0b0 · 11-20-2001, 07:25 PM

with the way dhcp works, a 'dhcp_request' packet by default asks for the same IP address back again. as long as no one requests and gets 'your' IP address, you will have the same one for quite a while...unless your ISP has rolling IP's.

jason