Synology DSM 6.2 DDNS "Failed to connect to the server" for Namecheap

 So DNS-O-Matic is shutting down, forcing me to find a new solution.

I was so happy to find that my Synology could do this too.  I was not so happy to find it didn't seem to work, with multiple users saying they never got it to work with Namecheap.

 

[Yes, my Synology is old, and is running 6.2.  I'm not dropping $5k on a new model that whines like a little bitch every time you stick in a new hard drive, even if Synology belatedly walked those back.  (More like ran those back, like sprinted.)  

Congratulations Synology, you've tarnished your brand forever, and are, and will now heretofore forever be, the textbook cautionary tale on how to alienate a loyal customer base.  Forever.]

My experience

It does work.  The NAS will throw an error every time it updates, but the NAS does still seem to update the Namecheap records correctly.

How to do it: 

1.  Follow the instructions here.  

 2. In my setup, I initially used the query URL:

https://dynamicdns.park-your-domain.com/update?host=@&domain=__DOMAIN__&password=__PASSWORD__&ip=__MYIP__

However, it seems that the MYIP part is not needed, so you could also use:

 https://dynamicdns.park-your-domain.com/update?host=@&domain=__DOMAIN__&password=__PASSWORD__

 3.  The other page says that "Hostname" is the domain you want to be updated (i.e. "mydomainname.com").  This did not work for me.

If you look at the query string (above), you will see that "host" is preset to "@".  So this field in the Synology form doesn't actually do anything.

You do need to fill something in here.  So I still put the domain name (i.e. "mydomainname.com").

4.  Username/Email:  The other page says this is your Namecheap user name.  This did not work for me.

If you look at the query string (above), you will see that there is no field for "user name".  I guessed this was actually the place to put the domain name (i.e. "mydomainname.com"), and that worked.

5.  Password/Key:  NOT your Namecheap account password, but the really long key generated by Namecheap specifically for DDNS (i.e. '7a0354e9ae547b9d30ab0ea4ff0a30f7').

 6.  Click "Test Connection".  DSM will barf an error message "Failed to connect to the server. Please check the network connection of the server."

  Side note:  One of the dumbest error messages of all time - people are smart enough to buy a NAS and gain access to the web UI, yet *somehow* forgot to plug in the bloody cable?  Really?

7.  Click "OK" anyway.

8.  Go back to Namecheap and check the "A + Dynamic DNS Record" for the domain.  In my case, it >had< actually updated despite the DSM error message(s).

 I can't swear it updated correctly the first try, or even the second try, as I was goofing with different query URLs trying to solve the issue.  But eventually I noticed that the above URL seemed to have worked on the Namecheap side.  

Actually, when it works, Namecheap updates almost instantly.  This makes sense, as Namecheap should register an update from the NAS as soon as it is made.

 9.  According to  Google Gemini (yes, I know....), you should remove any static "A Records", as they could conflict with your A+ Dynamic DNS Record.  

Having said that, I never noticed any issues at all when using DNS-O-Matic.  And I had domain names with no A Record, one A Record and even two A records (!), plus the A+ dynamic record.

 

Debugging:

You can manually test the query URL + password combbo by pasting the update string into your browser manually: 

1.  Replace "__DOMAIN__" with the domain, and "__PASSWORD__" with the long Namecheap-generated password:

 https://dynamicdns.park-your-domain.com/update?host=@&domain=updatethisurl.com&password=12bsge75moms5gg5x879q12bf355981e

2.  Copy and paste that into your browser.

3.  Tou will get a short, plaintext XML response.

4.  Look for the tag "ErrCount".  If the number is zero, then the query URL is working, and NameCheap is updating.

HOWEVER, you have only validated that Namecheap can receive your update and your password is correct, and NOT that your Synology is sending the update query in the right format.  Plus you've just manually updated your dynamic DNS record, so if you want to troubleshoot further, you'll have to reset it again.

 Obviously YMMV, but you may want to check Namecheap before deciding the the Synology DSM  DDNS updater isn't working - "Test connection" button be damned.