Re: Dynamic DNS problems on Synnology with Orbi RBR50V2 firmware 2.7.3.22

NESSHINDO · ‎2021-09-13

All of a sudden my Synology DS720 produces Dynamic DNS problems (xxx.synology.me). After quite a bit research the problem is most likey caused by the Orbi (see https://www.synoforum.com/threads/ddns-failed.6762/)

My Synology cannot get (mostly 5 or 6 times in a night) an external IP adres. Porwersaving is off in my Synology.

Turned of Daylight savings en Network monitoring on Orbi as suggested in other discussions. Anyone a clue?

FURRYe38 · ‎2021-09-13

What Firmware version is currently loaded?
What is the Mfr and model# of the Internet Service Providers modem/ONT the NG router is connected too?

Looking at the responces by others there, seems to be a ISP or DDNS service issue rather than a Orbi issue. I don 't see any comments about Orbi in that thread...

CrimpOn · ‎2021-09-13

Mention of the Orbi starts about page 3 of the thread. I get the impression that this might be another consequence of the V2.7.3.22 firmware. This thread provided an interesting perspective on DDNS. (which I enjoyed.) It had never occured to me that there could be any number of DDNS entries that resolve to the same public IP address. As long as the connection request refers to a port that has been forwarded to a specific IP on the LAN, any number of devices could be using DDNS. They just all have to have different ports on the Orbi WAN side.

I also noticed a comment that the Orbi debug page (at one time) had an option to prevent automatic firmware updates. I do not recall seeing any such option, at least in the past couple of years. A mystery.

FURRYe38 · ‎2021-09-13

Seems like there maybe a problem else where well before page 3 though.

I'll look to see if that option is there on my RBR50 with v22 loaded. I don't recall seeing that option either.

NESSHINDO · ‎2021-09-13

I have firmware 2.7.3.22. in my Orbi.

My ISP modem is Sagemcom F5359 (Experiabox V12 from ISP KPN in the Netherlands). It has a glass modem as well.

First i thought my NAS was causing the problem but the gut on the forum did so much research that he convinced me that the Orbi is causing the problem... My Orbi is in Routing mode. DNS on 8.8.8.8.

FURRYe38 · ‎2021-09-13

What mode is your modem working in? Bridge or Router mode?

Does changing from google DNS to ISP DNS do anything different? Changing DNS really shouldn't effect anything unless Synology requires something specific with there services. Something to ask them about.

NESSHINDO · ‎2021-09-13

My ISP router i cannot configure in Bridge mode. Is had only routed mode. Synology Engeneer put the DNS to Google ;-). First there was the DNS from my ISP.

Its a mysterie to me. Hoping for a new firmware on the Orbi...?

FURRYe38 · ‎2021-09-13

So your in a double NAT condition which isn't recommended with the ISP modem:

If you can't bridge the modem, disable ALL wifi radios on the modem, configure the modems DMZ/ExposedHost or IP Pass-Through for the IP address the Orbi router gets from the modem. Then you can use the Orbi router in Router mode.

Or disable all wifi radios on the modem and connect the Orbi router to the modem, configure AP mode on the Orbi router. https://kb.netgear.com/31218/How-do-I-configure-my-Orbi-router-to-act-as-an-access-point and https://www.youtube.com/watch?v=H7LOcJ8GdDo&app=desktop

Might try this as well and see if the problem continues or not.

Has this been working prior or to a prior FW udpate or is this new for you?

You'll need to contact NG support and let them know what your seeing and see it they can establish what mabye wrong before a FW update would be forth coming.

NESSHINDO · ‎2021-09-13

Thanks very much @FURRYe38 ! Done all the config recommendation you mentioned more than a year ago. With good result. All steady. But without config change a few weeks ago the connection problems occured.

FURRYe38 · ‎2021-09-13

So your using DMZ or IP pass thru on your modem?

Was that when v22 udpated on your system?

Might try a factory reset and setup from scratch...if not, you'll need to let NG support know about this. Revert back to a version of FW that worked for you.

NESSHINDO · ‎2021-09-14

I am using DMZ. Updates a few months ago. Sinds it was released. But my problem us for two weeks now.. tonight there were no connection problems till now. No config change....strange..

dbrewood · ‎2021-09-15

This is definitely an Orbi issue with firmware 2.7.3.22 I've confirmed it with Netgear Support after a lot of testing.

Alas there seems to be no way of fixing excepting hoping they bring out a fixed version of the firmware. This renders my Orbi system completely useless.

In the interim I've had to go back ot using the ISP's router/modem so lost all my mesh capabilitie.

The only fix woudl be to downgrade the firmware and stop it from auto-upgrading which seems no longer possible.

CrimpOn · ‎2021-09-15

@dbrewood wrote:

The only fix woudl be to downgrade the firmware and stop it from auto-upgrading which seems no longer possible.

There are two documented methods for preventing firmware auto-upgrade:

Disconnect the router from the internet (temporarily).
Manually load previous firmware.
Enable telnet.
Replace the file firmware_version with text where the first number is greater than any likely firmware release
(such as V5.2.7.104)
This will prevent auto-upgrade until the next time the router is rebooted.
With my Orbi on a UPS, it can go 5-6 months without rebooting. (A 4 hour power outage caused one.)
Use an upstream router to block the URL's used for firmware upgrading.
This, of course, makes applications such as OpenVPN and port forwarding more difficut.
(Not impossible, just more difficult.)

Since Netgear Support has acknowledged the issue, one might thing they would be willing to provide beta firmware in advance of general release. Sometimes beta firmware is read for test months before general release. (The QA proess for release appears to take some time.)

dbrewood · ‎2021-09-15

Thanks for the reply.

I'm aware of the option of using telnet however the firmware (V2.7.3.22) I have when I access the beta page does not have the option of turning telnet on. So I'm unable to use that option.

If I could identify what version of the firmware did have the telnet option I'd try it.

The ISP modem/router (British Telecom Home Hub 6) can't be dumbed down and DHCP turned off so that can't be used with the Orbi in AP mode. If it was used in normal mode we'd end up with a double NAT situation I think.

FURRYe38 · ‎2021-09-15

You can use your ISP modem/router to block the auto updates from happening.

Also if you want to use the Orbi in router mode with your ISP router, configure the ISP routers DMZ for use with the Orbi router. This helps avoid Double NAT issues. Works well.

@dbrewood wrote:

Thanks for the reply.

I'm aware of the option of using telnet however the firmware (V2.7.3.22) I have when I access the beta page does not have the option of turning telnet on. So I'm unable to use that option.

If I could identify what version of the firmware did have the telnet option I'd try it.

The ISP modem/router (British Telecom Home Hub 6) can't be dumbed down and DHCP turned off so that can't be used with the Orbi in AP mode. If it was used in normal mode we'd end up with a double NAT situation I think.

CrimpOn · ‎2021-09-15

@dbrewood wrote:

If I could identify what version of the firmware did have the telnet option I'd try it.

The ISP modem/router (British Telecom Home Hub 6) can't be dumbed down and DHCP turned off so that can't be used with the Orbi in AP mode. If it was used in normal mode we'd end up with a double NAT situation I think.

Any version prior to V2.7.3.22 has telnet on the debug page.

There may be a 'double negative' in the sentence above. For the Orbi to be in AP mode, then some other device (the BT router) must provide DHCP.

Note: we seem to have merged two issues into one post. (One from Netherlands. One from British Telecom.)

There are actually four method to handle Double NAT.

Eliminate Double NAT by putting the ISP device into bridge (passthrough) mode, leaving the Orbi as the only router.
This allows the Orbi to handle all 'router functions', such as DHCP, Port Forwarding, choosing DNS sources, assigning IP's, etc. etc.
Eliminate Double NAT by puting the Orbi into Access Point (AP) mode, leaving the ISP device to handle all DHCP, assigning IP's, port forwarding, Parental Controls, DNS, etc. etc. This has the benefit of allowing devices to be hard wired to the ISP router and preserves television capabilities.
Bypass Double NAT by putting the Orbi in the ISP device DMZ. If all user devices are connected to the Orbi, then the ISP router has only one device connected to it.
Live with Double NAT. If port xyz has to be forwarded to some device, Forward that port on the ISP router to the Orbi's IP, then forward that port on the Orbi to the device. This works, but is so much effort that most users would pick 1,2, or 3 instead.

dbrewood · ‎2021-09-15

Alas the BT ISP Router does not have any option to block any web traffic alas.

The only option I could do would be to change the Orbi IP address back to the default (I changed it to match the ISP router), set it as the DMZ in the ISP modem, and turn off DHCP on the ISP modem? Is this what you mean?

CrimpOn · ‎2021-09-15

@dbrewood wrote:

Alas the BT ISP Router does not have any option to block any web traffic alas.

Which of these is your BT Home Hub 6?

https://www.bt.com/help/broadband/getting-set-up/user-guides-and-manuals-for-bt-hubs

dbrewood · ‎2021-09-15

Yep looks like some thread merging indeed.

Thanks for those 4 suggestions.

1) is out as the ISP modem doesnt support pass though alas.

2) or 3) coukd be viable things to try. Which woukd you recommend I try first? 2) I guess?

dbrewood · ‎2021-09-15

@CrimpOn wrote:
Which of these is your BT Home Hub 6?
https://www.bt.com/help/broadband/getting-set-up/user-guides-and-manuals-for-bt-hubs

It's the BT Smart Hub (Type B) Fibre to the cabinet (FTTC). I have ADSL coming in .....

CrimpOn · ‎2021-09-15

@dbrewood wrote:

Yep looks like some thread merging indeed.

2) or 3) coukd be viable things to try. Which would you recommend I try first? 2) I guess?

I am no longer certain which issue we are trying to solve:

There is a DDNS issue with the Synology NAS which is caused by Orbi V2.7.3.22 and we want to prevent the Orbi from updating to that version.
There is some other issue we are trying to solve.

None of these Double NAT strategies will address the auto-upgrade issue.

dbrewood · ‎2021-09-15

@CrimpOn wrote:
Any version prior to V2.7.3.22 has telnet on the debug page.

I had missed the above, I may look to do a downgrade and then try the telnet fix to disable updating.

Eliminate Double NAT by puting the Orbi into Access Point (AP) mode, leaving the ISP device to handle all DHCP, assigning IP's, port forwarding, Parental Controls, DNS, etc. etc. This has the benefit of allowing devices to be hard wired to the ISP router and preserves television capabilities.

If I went with that option would the Orbi still be able to use the Wireless mesh?

CrimpOn · ‎2021-09-15

The Advanced Setting on page 10 do not have anything resembling "Block Sites"?

https://www.bt.com/content/dam/bt/help/legacy-ug/new-pdf/BT%20Smart%20Hub%20(Type%20B)%20Fibre%20to%...

dbrewood · ‎2021-09-15

@CrimpOn wrote:
@dbrewood wrote:
Yep looks like some thread merging indeed.
2) or 3) coukd be viable things to try. Which would you recommend I try first? 2) I guess?
I am no longer certain which issue we are trying to solve:
There is a DDNS issue with the Synology NAS which is caused by Orbi V2.7.3.22 and we want to prevent the Orbi from updating to that version.
There is some other issue we are trying to solve.
None of these Double NAT strategies will address the auto-upgrade issue.

I'm trying to get round the DDNS issue (which is actually an issue of DNS being blocked I believe). So yes I want to bo back t the prior firmware and stop the Orbi updating.

The thought was if DNS etc was run on the ISP router it'd bypss the problems? Hence the double NAT questions I thinkl

CrimpOn · ‎2021-09-15

@dbrewood wrote:

I'm trying to get round the DDNS issue (which is actually an issue of DNS being blocked I believe). So yes I want to bo back t the prior firmware and stop the Orbi updating.

There are only two methods to prevent the Orbi from auto-updating firmware:

Put a router between the Orbi and the Internet and use it to block access to the Netgear update web sites.
(Shame that the BT Advanced Settings will not do that.)
Because this will create a Double (or Triple) NAT, the Orbi will probably be better off in AP mode.
In your case, this leaves you with a Double NAT to get around. Does the BT Hub offer a DMZ?
Use telnet to change the file firmware_version in the Orbi root directory to begin with a number larger than the latest firmware.
V2.7.3.22 is the latest, so my personal practice is to load a previous version, such as V2.7.2.104 and change the first 2 to something BIG, such as V5.7.2.104.
Then, keep the Orbi from rebooting, which will cause it to reset the version number and promptly update firmware.
I use a substantial UPS so that minor power outages do not cause my Orbi to reboot.

This topic is really awkward because I have no Synology NAS and cannot investigate the primary issue. I am unable to come up with any reason how the Orbi's handling of DNS could impact the NAS. If the NAS can be set with a static IP, then surely it can be set to entirely bypass the Orbi DNS process????