DDNS failed.....

[tekguru]

I'm seeing an issue today whereby the DDNS settings on the DS918+ are blank (instead of the external IP being shown) and the NAS is reporting there is no external connectivity. On checking the Synology account for the connection that reports all is normal.

I've rebooted the NAS and it looking at the Synology account it now shows that DDNS is offline. Hostname and IP blanked out...

Any ideas folks?

 

[tekguru]

I meant to ask you if using your Cloudflare DDNS can you use it to still access the NAS remotely?

 

[Bogey]

I meant to ask you if using your Cloudflare DDNS can you use it to still access the NAS remotely?

Yes, the script works perfect. It updates the IP address of my domain at Cloudflare and traffic is routed by Cloudflare to my proxy that on its turn directs it to the correct app/site.
Oh you, mean remote access? Yes that works too.

 

[tekguru]

Right I guess you need to have your domain hosted with Cloudflare for that to work though?

 

[Bogey]

That's correct. It's not a subdomain like yournas.synology.me
But these days a full domain name is dirt cheap (you have to be aware that the costs of renewal should be taken into consideration where to register the domain, or else the next year isn't so dirt cheap. I suggest consulting Compare Prices of All Top-Level Domains | TLD List).

 

[tekguru]

I’m aware however I’ve just moved my spare domains to a new registrar within the last 3 weeks. My main domain is also hosted with Microsoft and tied into Office 365 so very messy to adjust alas. Sigh.

 

[Bogey]

And that's why I use Cloudflare
A correct DNS setup allows you to do what you want plus DDNS.
Just like mynas.synology.me I use a subdomain: mynas.mydomain.com
On Cloudflare I have one (1!) extra DNS entry: A record for mynas.mydomain.com.
The script (GitHub - mrikirill/SynologyDDNSCloudflareMultidomain: Synology DDNS Cloudflare service provider with multidomains and subdomains) updates the IP address of mynas.mydomain.com at Cloudflare. Everything else (I'm not using Microsoft, but Zoho) remains as it is.

-- post merged: 27. Sep 2021 --

Oooh and Cloudflare as a nameserver isn't the same as Cloudflare as a registrar!
When using Cloudflare as a nameserver, they ask if all current DNS entries should be taken over.

 

[tekguru]

Yep aware of that I’ve been running forums and domains etc for 20+ years. I too use sub domains for the forum I host on the NAS as well as accessing the NAS UX via the web. The problem is those sub domains point at the xxx.Synology.me quick connect address and when the DNS problem hits that goes offline. I did try to use DDNS on the Orbi router but that only gets me to the router, if the NAS can’t respond back for things like the Maria database etc it does not help alas and I’m still screwed by DSM7.

-- post merged: 27. Sep 2021 --

So thinking on it I’ve used No-IP as an alternative DDNS entry but as the DNS issue stops the outgoing connectivity then alas Cloudflare would fail with the same issues for me.

 

[Bogey]

So your subdomains point to synology.me, as in CNAME record points to CNAME? And your No-IP test is the same construction? That would mean there’s something wrong with Synology’s script, right?

The Cloudflare script I use is not written by Synology. It’s not just selecting Cloudflare from the dropdown, but a totally different script.
The error on my NAS only starts when I use Synology.me next to the Cloudflare script.

 

[tekguru]

Yep completely correct. It was the only way I could get it to work, I point my forum.domain.com to the mynasname.synology.me which worked perfectly from when I started hosting the forum in February.

The DDNS fails as the NAS when the DNS issue occurs can’t get out to the internet past the Orbi router. Again no problems with that until DSM7. Weirdly enough if I put the ISPs terrible basic router in place and use the Orbi in AP mode then all works well.

So Synology changed something in DSM7 that conflicts with Orbi. If I ping 8.8.8.8 or do an nslookup on it (some of the tests they have asked me to run) they fail at the gateway which is of course the Orbi.

Anyway they have come back overnight with more logging out in place and want me to do some packet capturing tests. Can do any of those alas until I get home from the break.

Your Cloudflare script would likely fail for me too as the problem looks to actually be a DNS resolution problem.

 

[Bogey]

Hmmm…
Perhaps naive, ignorant or plain dumb idea, but could it be that your ISP’s router has UPnP enabled and your Orbi not?

In my configuration outside connections are going through port 443 on my Fritz modem (I don’t have it in bridge mode), my Fritz forwards to the Asus router on a different internal port, the Asus forwards to the proxy on the NAS. I use a different port than 443 to prevent conflict on the NAS. The proxy then handles the “subdomain to port conversion” to the various sites/apps. I don’t think this setup is any different then yours, right?

-- post merged: 28. Sep 2021 --

Oh, I do have one docker container (that connects via a VPN) that requires UDP ports 53 and 443 to be open on the NAS’ firewall — I could not get it to work in any other way.

 

[tekguru]

Strangely enough I wondered about UPnP but again it all worked as it is configured now prior to migrating from DSM6 to DSM7.
Your setup is a lot more complex than mine as (ideally) I just have the Orbi in place as the main router with various ports forwarded to the NAS.

 

[tekguru]

Hmmm I see DSM 7.0.1-42218 is out. I wonder if that is worth trying?

 

[tekguru]

Well updating to DSM 7.0.1-42218 didn't fix the issue. What is more worrying is that the loss of connection and failure to register DDNS seem to be no longer showing in the Log Center.
Anyway, I've managed to capture the packets for Synology and have just sent the files on to them.
Oh and out of desperation I have altered the Orbi settings and turned UPnP back on.

 

[tekguru]

Well another packet capture has been sent to Synology and UPnP on the Orbi is off again as it didn't help.

This time the dop in connectivity did show in the log. Weird.

 

[WST16]

Take a look at @AdrianEarnshaw spreadsheet. A few changes here and there and you’re set for a new router
Sorry, as usual I couldn’t resist
But I really admire your persistence.

 

[tekguru]

LOL I did read that thread earlier......

-- post merged: 4. Oct 2021 --

It's definitely DSM7 that is the issue and not the router. The dev team at Synology think they have an idea which way to go and are actively working on the issue.

 

[dorsi]

Yep I'm pretty convinced it is some sort of weird conflict between DSM7 and the Orbi. The Orbi had been running flawlessly from December right until I did the DSM7 upgrade. Then the problems occurred.
Synology says it is the Orbi. Netgear say there should not be any problems with the Orbi and the latest firmware was issued to fix DDNS issues.

@dorsi did you raise a support ticket with Synology at all?

I wish there was somebody on here running DSM6 with an Orbi running the latest firmware who could state they have no problems at all.

@Seaprobe is it an Orbi you're using too?

I wish Synology would own up to the issue.

I opened a support ticket and their assistance didn’t help. But I’ve found the issue.

It’s Netgear Armor that’s been turned on within Orbi. I originally tried to disable Netgear armor from monitoring my NAS but that didn’t help. Two days ago I disabled Netgear Armor COMPLETELY within the Orbi options and it hasn’t happened since.

 

[tekguru]

I can see where you are coming from with that, but I'm still not convinced that is the issue. Running vDSM6 with Orbi Armor in place works flawlessly without a single problem.

So I think it is more likely that Synology have changed something in DSM7 take makes it trigger Armor?

Keep me posted though as to how you go as it may help Synology / Netgear to solve the issue.

 

[tekguru]

Interestingly the problem just occurred again for me and I turned off Armor (as you advised) and the issues went away, well I could update DDNS anyway).
I've turned Armor back on now and will see if turning it off fixes it next time around. If it does I can at least tell Synology that whatever they have changed in DSM7 conflicts with Armor.

[Update] - I've just gone into Armor and removed the NAS as a device in the system. If it does not reappear this might be the needed work around. Fingers crossed.

[Update 2] - A thought this issue does affect other users who are not using the Orbi system, so Armor is not involved on their systems....

 

[tekguru]

The problem just occurred again and I turned off Armor and the DNS / connectivity issue went away, I could update DDNS as soon as I got to the control panel.

I've turned Armor back on and removed the secondary entry I had for the NAS in it. So again I'll see how it goes.