[MatteoDubai]

I am setting up a DynDns with Dynu.com (used firmware: DD-WRT v3.0-r47911 std (12/23/21))

Everything works great, however, I have 2 questions:

1) How can I set up the refresh time for the IP to 5 min? I will need to have 1 router with DDWRT at home that will be the VPN server and 1 router in another country (where I live) with DDWRT that will be the VPN client. I will need to make sure that the server IP is refreshed every 5 min to be always updated. The minimum refresh time is 1 day on the configuration page in DDNS.

2) I followed the instructions on the Dynu website and as password I used the SHA256 instead of the password in the configuration, can I make the DDNS even more secure somehow?
The Dynu account is protected with a 20 chars random password tied to a Google account protected with 60 chars random password and 2FA.

[egc]

for almost all providers it is 600 sec see:
cat /tmp/ddns/inadyn.conf

the "--update_period_sec" will show the seconds between updates.
The value you are referring to is the forced update, it will update even if it is not necessary.

You can only change this value manually then kill the inadyn process but before you do that look at the way to restart it (ps from CLI)

[MatteoDubai]

Thank you for the quick reply.

Can I reboot the router to restart the process?

Regarding the security, can I do something to make it more secure? Exposing the DDNS and the VPN server over the internet I would like to make sure I have maximum security.

[egc]

[spyfly]

Could a command be programmed at router startup to change that value from 86400 to another value like 3600 for example?

could you make a scheduled cron job to force the ddns update?

[egc]

[spyfly]

I am checking https://wiki.dd-wrt.com/wiki/index.php/Dynamic_DNS#Debugging_your_configuration thank you

the option to force update faster (cad 3600 seconds) is very necessary, there is no sense in a 24 hours forced update, it is too much.

[ho1Aetoo]

Do not do this, most dyndns providers have update policies

Spam leads to suspension of the account

[spyfly]

Is it possible to do something like this?

1. Execute by hand:

cd /tmp/ddns
cp /tmp/ddns/inadyn.conf /jffs/inadyn.conf
vi /jffs/inadyn.conf



2. Save this script in the firewall so that it executes itself:

killall inadyn


inadyn --cache-dir=/tmp/ddns -e ddns_success --exec-mode=compat -f /jffs/inadyn.conf -P /var/run/inadyn.pid -l info -t 30 -C

[egc]

[spyfly]

the theory was very nice but when I put it into practice it does not let me.

The command cp /tmp/ddns/inadyn.conf /jffs/inadyn.conf does not create a copy of the file. if once executed, I do
cd /jffs/
ls
I see that there are no files in that path

it also does not work to create the file by hand with:
vi /jffs/inadyn.conf
when I save it with ESC + :wq it tells me that it is read-only

even mkdir /jffs/ddns doesn't create the directory either

It is as if I cannot write to /jffs/.

[egc]

[spyfly]

as I can't write in jffs to create my own inadym configuration, could I force with a scheduled task in cron the update fast?

so i can use cron job like this: 3,8,13,18,23,28,33,38,43,48,53,58 * * * * sleep 20 ; curl -s -S "https://www.duckdns.org/update?domains=DDDDDDDDD&token=TTTTTTT-TTTT-TTTT-TTTT-TTTTTTTTTTTT" >> /var/log/dyndns.log 2>&1 &

or this 3,8,13,18,23,28,33,38,43,48,53,58 * * * * sleep 43 && printf "$(date "+%Y-%m-%d %T") " >> /var/log/dyndns.log && curl -s -S "https://www.duckdns.org/update?domains=XXXXXXXXXXX&token=XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX" > /var/log/dyndns.log && printf "\n" >> /var/log/dyndns.log 2>&1 &

[egc]

You can research how to make a writable /jffs (hint USB, JFFS2) or simply make a cron job to restart DDNS.

Just some suggestions

[spyfly]

From telnet I have tested it and it works with: