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"

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