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?

 

[WST16]

The firewall shouldn’t impact the DDNS updates, it originates from the NAS (outbound). The firewall is for inbound traffic.
The only time this happens on my DiskStations is when I have a network issue.
Did you try to continuously ping the DS and checking for dropped packets.
Also, did you try changing to the other port (if it’s not used).

 

[tekguru]

Ah ah right, I was wondering as I was geoblocking non-UK traffic (I've turned that off for now).
As far as I'm aware I never have any network issues. The network is rock solid. I've only had these issues since moving to DSM7.
I hadn't but I am now, nothing looks to be dropping. Plus the DDNS issue can last for hours during which time the NAS is fully online and accessible on the network.
Yep i have tried changing the port, seems not to make any difference.

 

[WST16]

“Have you tried turning it off and on again?” – IT crowd.

 

[tekguru]

LOL yep rebooted it twice, does not make any difference...... I'll have to wait on Synology getting back to me I guess.

I can't think of what else I can try ...

 

[WST16]

Maybe I missed it on the thread, but did you try changing to a different port on the switch?

 

[tekguru]

Yep tried two different ports on the switch and also two different ports on the router too. Again no difference.

 

[WST16]

Might be your lucky day. The planets in your horoscope today (yesterday?) are aligned the right way and a bug might’ve found its way to your DSM 7.0
A bug in a .0 release, how dare they do that

They’ll tell you it’s your network and that DSM 7.0 is “streamlined” and is capable of updating a DDNS’ external service even if the stars are not aligned correctly anytime of the day.

@jeyare is building a super duper NAS, would you like one?

 

[tekguru]

Indeed.......

I guess there is no way of downgrading back to DSM6?

 

[Rusty]

I guess there is no way of downgrading back to DSM6?

DSM 7 to DSM 6 downgrade (unofficial and unsupported)

Jumped the gun on updating to DSM7? Want to go back to DSM6? This unofficial and unsupported method might help out.

www.blackvoid.club

 

[fredbert]

I do my DDNS on the RT2600ac. On the NAS I have deactivated, fallback DDNS settings configured in case I need them. Haven't been experiencing any issues with SRM doing this.

 

[tekguru]

Eek, I'll avoid that downgrade it looks scary!

Right so I could use the DDNS on the Orbi router instead maybe? Hmmmmm How did you configure DDNS fallback?

I've been meaning to ask for ages, what is SRM?

 

[fredbert]

Hmmmmm How did you configure DDNS fallback?

Maybe I wasn't precise enough. I used to use the NAS for DDNS for my personal domains (via DNS-o-Matic) but that rule is now deactivated, but not deleted, with only the Synology DDNS enabled. The SRM router does the DNS-o-Matic rule now.

The fallback is achieved by manually re-enabling the DDNS rule on the NAS, or use DNS Broker on an always-on Mac. It's so high tech!

Synology's routers run SRM, like their NAS run DSM... I guess Synology Router Manager?

 

[tekguru]

Ah ha.... Right I'm with you now.

The Netgear router supports DDNS via Netgear, www.No-IP.com or www.Dyn.com. The Netgear option is actually a branded No-IP account, and alas from March 1, 2021, all free mynetgear.com hostnames have to be manually confirmed once every 30 days or they are deleted from their system. To avoid that limitation it'll cost $24.95 a year. Somewhat annoying.

Right so at least I don't have to worry about SRM references

 

[fredbert]

If you have an always-on Mac then you could look at dDNS Broker - The Ultimate dDNS Update Client for Mac which is $5/£5 on the Mac App Store. I did use it successfully until moving to the NAS and then SRM router as DDNS client.

 

[tekguru]

It is a possible solution, but so inelegant. I just want it to work how it should.

I had a chat with Marius Bogdan Lixandru over the issue and he suggested setting the DNS to Google's servers (which I already had set) but then rebooting the NAS after the change was confirmed. I've done that so we'll see what transpires from here.

 

[tekguru]

A further update. The forum again went offline so I checked the DDNS status on the NAS (it was showing the fail messages again), I then checked to see if I could access the forum using the DDNS hostname configured on the router, that too failed.

I then checked the router DDNS status and that reported it was working and it returned the correct external IP on the router.

Next on the Mac I used nslookup to check xxxx.synology.me, again that returned the correct IP address. I then used nslookup to check ddns.synology.com and it resolved without issue.

This tells me that it is not a network error with connectivity and that the NAS itself is suffering a breakage with how it receives the WAN data on the HTTP/HTTPS ports.

Does this make sense?

 

[Rusty]

Does this make sense?

It might but why did you also had problems on the router side is what’s bothering me

 

[WST16]

I then checked to see if I could access the forum using the DDNS hostname configured on the router, that too failed.

I assume the “forum” is your internally, NAS-hosted forum. Anything in the logs (log center)?
When I have connectivity issues on the NAS, I have “link down” followed by “link up” in the logs.

A desperate idea that might not be so effective, is to put a switch (if you have a spare one) between the NAS and the Netgear router and see if it makes any difference. So we decouple the NAS from the Netgear port to test.

 

[tekguru]

It might but why did you also had problems on the router side is what’s bothering me

To clarify, the router DDNS was active and working (according to the DDNS checker in the router config) but if I tried to connect using the router DDNS hostname then I got the same as with the DDNS on the NAS. This again validates to me it's not a network issue, it's almost as the NAS is blocking the incoming forwarded ports.

I assume the “forum” is your internally, NAS-hosted forum. Anything in the logs (log center)?
When I have connectivity issues on the NAS, I have “link down” followed by “link up” in the logs.

A desperate idea that might not be so effective, is to put a switch (if you have a spare one) between the NAS and the Netgear router and see if it makes any difference. So we decouple the NAS from the Netgear port to test.

Log errors include:

Error​

System​

2021/08/29 20:28:03​

SYSTEM​

System failed to get External IP.​

Error​	System​	2021/08/29 11:52:23​	user​	Failed to send email. (Failed to connect to mail.smtp2go.com:587).​
Error​	System​	2021/08/29 11:52:22​	user​	System config backup failed due to a broken Internet connection​

Error​	System​	2021/08/29 11:08:47​	SYSTEM​	System failed to get External IP.​
Error​	System​	2021/08/29 03:57:41​	SYSTEM​	Failed to send email. (Failed to connect to mail.smtp2go.com:587).​
Error​	System​	2021/08/29 03:17:47​	SYSTEM​	System failed to get External IP.​

Error​	System​	2021/08/25 20:18:50​	user​	Failed to send email. (Failed to connect to mail.smtp2go.com:587).​
Error​	System​	2021/08/25 20:18:49​	user​	System config backup failed due to a broken Internet connection​
Error​	System​	2021/08/25 20:02:47​	SYSTEM​	System failed to get External IP.​
Error​	System​	2021/08/25 18:44:47​	SYSTEM​	System failed to get External IP.​

All very similar as you can see.

I did try as part of my testing to switch the NAS into the switch I have in the network and alas it didn't make any difference.

I did reboot the router this morning to see if that would make any difference but saying that it'll be the third time I've rebooted it this week to rule that out. But I'd not rebooted since I rebooted the NAS last night.

The only thing I can think of now is to hook an ethernet cable to the second LAN port and assign the port forwarding to use that port instead of the primary. Not sure though if that would cause problems on the NAS or on the network itself?

 

[WST16]

When you go to log center, do you see anything like the below:

I'm trying to find out if DSM detects a drop in connectivity. If the network is intact then the problem lies elsewhere.