Shell script to update namecheap.com dynamic dns for a domain with your external IP address

namecheap-ddns.sh

#!/bin/sh

# Shell script to update namecheap.com dynamic dns
# for a domain to your external IP address

HOSTNAME=yoursubdomain
DOMAIN=yourdomainname.com
PASSWORD=y0urp455w0rd

IP=`curl -s echoip.com`

curl "https://dynamicdns.park-your-domain.com/update?host=$HOSTNAME&domain=$DOMAIN&password=$PASSWORD&ip=$IP"

Not sure if this is new feature of namecheap dynamic DNS, but if you're just going to set it to the IP you're calling the URL from, then no need to specify the IP, it is determined automatically.
(reduces the dependency in another 3rd party service)

IP Address = optional value. If you don't specify any IP, the IP from which you are accessing this URL will be set for the domain

https://www.namecheap.com/support/knowledgebase/article.aspx/29/11/how-do-i-use-a-browser-to-dynamically-update-the-hosts-ip/

Just use:

curl "https://dynamicdns.park-your-domain.com/update?host=$HOSTNAME&domain=$DOMAIN&password=$PASSWORD"

Awesome, worked like a charm on my tomato router. Thanks all!

Minor change to only update the dynamic DNS record when required. Allows for frequent update checking without hammering the namecheap update API.

#!/bin/sh

# Shell script to update namecheap.com dynamic dns as required
# for a domain to your external IP address

HOSTNAME=yoursubdomain
DOMAIN=yourdomainname.com
PASSWORD=y0urp455w0rd

CURRENT_IP=$(curl ifconfig.io)
DYN_IP=$( host "$HOSTNAME.$DOMAIN" | sed -e "s/.*\ //" )

if [ "$DYN_IP" != "$CURRENT_IP" ]; then
    curl "https://dynamicdns.park-your-domain.com/update?host=$HOSTNAME&domain=$DOMAIN&password=$PASSWORD"
fi

This works fine if HOSTNAME has a value, like 'www'. That would update the DNS for www.yourdomain.com.

I tried setting HOSTNAME to '@' to update the base domain (yourdomain.com) but got an error. Then I tried setting it to '', also no good. How to set the DNS value of @?

Does this work? (I can't test it right now)

host=@
domain=your-own-domain.tld
password=your-own-password
response=$(curl -s "https://dynamicdns.park-your-domain.com/update?host=$host&domain=$domain&password=$password&ip=$ip")
echo $response

No, it does not. I had mentioned that I tried this :( Mike

Here's namecheap's own documentation, unless I'm missing something we're updating using the described method:

https://www.namecheap.com/support/knowledgebase/article.aspx/29/11/how-to-dynamically-update-the-hosts-ip-with-an-http-request/

One thing to double check, on your namecheap DNS you do have the @ record host type set to "A+ Dynamic DNS record" ?

If that's correct then I'd open a support case with namecheap.

I had not created the @ record. When I created it just now, I set it to type "A record", not "A+ Dynamic DNS record" and there was no error message in response to: curl "https://dynamicdns.park-your-domain.com/update?host=$SUBDOMAIN&domain=$DOMAIN&password=$PASSWORD&ip=$IP" Seems to work, is there a reason to use "A+ Dynamic DNS record" instead of "A Record"? Mike

According to this you should be using the "A+ Dynamic DNS record". Whilst it might work now with a regular "A record" there's a chance that functionality will be deprecated in the future YMMV.

I set the types for the "@" and "www" subdomains to "A+ Dynamic DNS record" but when I saved the modified records, the types reverted to "A record". Mike

Here's something that brings together several of the ideas above.

• Prevents clobbering the Namecheap update servers
• Only relies on core internet services from OpenDNS/dnsOmatic infrastructure (robust and purpose buit for ddns use cases)
• Will also discover AWS public DHCP IP addresses properly if you have a lot of internal RFC1918 DNS going on.

#!/bin/sh
# Shell script to update Namecheap.com dynamic dns

DDNS_HOSTNAME=hostname
DDNS_DOMAIN=example.com
DDNS_PASSWORD=XXXXXXXXXXX

CURRENT_IP=$(curl myip.dnsomatic.com)
CURRENT_DDNS=$(dig +short $DDNS_HOSTNAME.$DDNS_DOMAIN @resolver1.opendns.com)

echo "current Namecheap ddns record = $CURRENT_DDNS"
echo "current AWS public IP address = $CURRENT_IP"

if [ "$CURRENT_DDNS" != "$CURRENT_IP" ]; then
    curl "https://dynamicdns.park-your-domain.com/update?
host=$DDNS_HOSTNAME&domain=$DDNS_DOMAIN&password=$DDNS_PASSWORD&ip=$CURRENT_IP"
fi

What the heck is park-your-domain.com and why would I send them my namecheap credentials? Is this a scam?

A simple search will lead you to NameCheap’s own documentation which shows that is the URL you use to update your dynamic dns with them.

…

On Sun, 14 Jan 2024 at 13:49, Alex Spurling ***@***.***> wrote: ***@***.**** commented on this gist. ------------------------------ What the heck is park-your-domain.com and why would I send them my namecheap credentials? Is this a scam? — Reply to this email directly, view it on GitHub <https://gist.github.com/dalhundal/89159b3f032588586e91#gistcomment-4830303> or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAEIXZJLDH6CTVU33FIL4QLYOPO5RBFKMF2HI4TJMJ2XIZLTSKBKK5TBNR2WLJDUOJ2WLJDOMFWWLO3UNBZGKYLEL5YGC4TUNFRWS4DBNZ2F6YLDORUXM2LUPGBKK5TBNR2WLJDHNFZXJJDOMFWWLK3UNBZGKYLEL52HS4DFVRZXKYTKMVRXIX3UPFYGLK2HNFZXIQ3PNVWWK3TUUZ2G64DJMNZZDAVEOR4XAZNEM5UXG5FFOZQWY5LFVAYTCNJRHE3TQONHORZGSZ3HMVZKMY3SMVQXIZI> . You are receiving this email because you authored the thread. Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub> .

Thanks - I did search and didn't find any mention of park-your-domain.com in Namecheap's documentation. Why don't they use namecheap.com or api.namecheap.com as their API domain?

Documentation: https://www.namecheap.com/support/knowledgebase/article.aspx/583/11/how-do-i-configure-ddclient/ As for why they chose to use that domain, that would be a question best directed at them.

…

On Sun, 14 Jan 2024 at 14:15, Alex Spurling ***@***.***> wrote: ***@***.**** commented on this gist. ------------------------------ Thanks - I did search and didn't find any mention of park-your-domain.com in Namecheap's documentation. Why don't they use namecheap.com or api.namecheap.com as their API domain? — Reply to this email directly, view it on GitHub <https://gist.github.com/dalhundal/89159b3f032588586e91#gistcomment-4830332> or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAEIXZKL4OYBPIHBDAW6UVTYOPR7BBFKMF2HI4TJMJ2XIZLTSKBKK5TBNR2WLJDUOJ2WLJDOMFWWLO3UNBZGKYLEL5YGC4TUNFRWS4DBNZ2F6YLDORUXM2LUPGBKK5TBNR2WLJDHNFZXJJDOMFWWLK3UNBZGKYLEL52HS4DFVRZXKYTKMVRXIX3UPFYGLK2HNFZXIQ3PNVWWK3TUUZ2G64DJMNZZDAVEOR4XAZNEM5UXG5FFOZQWY5LFVAYTCNJRHE3TQONHORZGSZ3HMVZKMY3SMVQXIZI> . You are receiving this email because you authored the thread. Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub> .

I made a couple of changes:

• Permits using "@" where you only have the TLD
• "silenced" the first curl
• Displays the Host and Domain values
• Changed the "dig"s to query dns1.registrar-servers.com since those are currently what NameCheap updates

#!/bin/bash
# Bash script to update Namecheap.com dynamic dns

DDNS_HOSTNAME="@"
DDNS_DOMAIN="YourDomainHere.com"
DDNS_PASSWORD="01234567890123456789012345678901"

CURRENT_IP=$(curl -s myip.dnsomatic.com)
if [[ "$DDNS_HOSTNAME" == "@" ]]; then
  CURRENT_DDNS=$(dig +short $DDNS_DOMAIN @dns1.registrar-servers.com)
else
  CURRENT_DDNS=$(dig +short $DDNS_HOSTNAME.$DDNS_DOMAIN @dns1.registrar-servers.com)
fi

echo "Hostname: $DDNS_HOSTNAME; Domain: $DDNS_DOMAIN"
echo "current Namecheap ddns record = $CURRENT_DDNS"
echo "current public IP address = $CURRENT_IP"

if [ "$CURRENT_DDNS" != "$CURRENT_IP" ]; then
    curl "https://dynamicdns.park-your-domain.com/update?host=$DDNS_HOSTNAME&domain=$DDNS_DOMAIN&password=$DDNS_PASSWORD&ip=$CURRENT_IP"
fi