Joined: 05 Oct 2008 Posts: 850 Location: Helsinki, Finland / nr. Alkmaar, Netherlands
Posted: Sat Aug 09, 2025 9:15 Post subject: R7800 and XR500 frequent random restarts
I have an R7800 in one location and an XR500 in another. Both run a recent or the latest build, which on the R7800 is currently r62036.
I don't know on which build it started to happen, but on all recent builds both routers restart one or more times within 24 hours.
The Keep Alive setting has them restart in the early hours every day.
There's also a watchdog setting with three IP's. I've seen that in operation a few times before and it leaves clear messages in the RSyslog I collect on a local server.
The random restarts I now see don't leave any messages in the log.
I've not noticed memory slowly getting filled up. Used and Available are around 40%.
I have no SFE activated on these routers.
Settings on both routers are similar - same author - and have been so for a long time except for Networking because of the changes of late. Both have separate networks for guests and IoT stuff. The R7800 also has a port dedicated to 4 small servers running BOINC and Folding at Home (also a separate network). I don't know the precise technical jargon to describe this. Sorry.
Neither router is very busy IMO. The restarts haven't been all too disruptive, but the only other human user tends to get annoyed when something bad happens on our network as "our friends don't have these problems".
There's an off-site backup routine running between the two locations at 3 h intervals, but sometimes without thinking I restart the network when the backup is running and in the end even that causes no problems (rsync ...).
On this forum I've seen reports of random restarts of an R7800 but with a much lower frequency of many days.
Joined: 16 Nov 2015 Posts: 7065 Location: UK, London, just across the river..
Posted: Sat Aug 09, 2025 12:55 Post subject:
hmmm my x2 R7800 nor XR500 dont have any self reboot/restart issues...both have similar configs...
my first thoughts:
-do you have CPU governor script - remove it
-PSU problems
-bad config
-compromised hardware
If your ram goes low, yes it will reboot, if hardware radio issues, yes it will reboot, if over heated reboot will happen too...
first things to try....reset and manually reconfigure and test to see settings that will compromise...it may take a long time
otherwise serial log will help a lot...the one and only... _________________ Atheros
TP-Link WR1043NDv2 -DD-WRT 62606 Gateway/DoT,Forced DNS,Ad-Block,Firewall,x4VLAN,VPN
TP-Link WR1043NDv2 -Gargoyle OS 1.15.x AP,DNS,QoS,Quotas
Qualcomm-Atheros
Netgear XR500 -DD-WRT 63257 GTW/SmDNS/DoT,AD-Blk,Forced DNS,AP&Net Isolation,x2VLAN,Vanilla
Netgear R7800 --DD-WRT 62606 Gateway/DNSCryptv2,AD-Block,Forced DNS,AP&Net Isolation,x3VLAN,Firewall,Vanilla,VPN cli
Netgear R9000 --DD-WRT 62606 Gateway/DoT,AD-Block,AP Isolation,Firewall,Forced DNS,x2VLAN,Vanilla
Dynalink DL-WRX36-DDWRT 62606
Broadcom
Netgear R7000 --DD-WRT 63257 GTW/DNScrypt-proxy2/AD-Block,IPset Firewall,Forced DNS,x4VLAN,VPN cli
NOT USING 5Ghz ANYWHERE
------------------------------------------------------
Stubby DNS over TLS I DNSCrypt v2 by mac913
Joined: 05 Oct 2008 Posts: 850 Location: Helsinki, Finland / nr. Alkmaar, Netherlands
Posted: Sat Aug 09, 2025 13:52 Post subject:
Alozaros wrote:
hmmm my x2 R7800 nor XR500 dont have any self reboot/restart issues...both have similar configs...
my first thoughts:
-do you have CPU governor script - remove it
-PSU problems
-bad config
-compromised hardware
If your ram goes low, yes it will reboot, if hardware radio issues, yes it will reboot, if over heated reboot will happen too...
first things to try....reset and manually reconfigure and test to see settings that will compromise...it may take a long time
otherwise serial log will help a lot...the one and only...
No CPU governor in use (as it is said to be useless for saving power).
Original PS ... should be up to the task
bad config ... possibly, but mostly has been in use for a very long time.
hardware ... I have a spare R7800 in the closet, so I could try that, but
It gets hot in this cottage, too. Some 30 degrees when the sun is shining. The highest of all temperature shown in the GUI is for nss1 and the value is just 57 degrees now (sun shining outside, room temperature 30 degrees). That shouldn't be a problem, I think.
I think I'll have to go for the reconfiguring. After all, these days I do have meticulous backups of the settings in HTML pages. First stop the 4 servers on the separate LAN/port altogether.
Reset NVRAM and reconfigure bit by bit as you suggested.
It looks like the R7800 has restarted again some 3-4 hrs ago. It had already restarted one time at least this morning after its Keep Alive restart in the wee hours.
Joined: 05 Oct 2008 Posts: 850 Location: Helsinki, Finland / nr. Alkmaar, Netherlands
Posted: Sat Aug 09, 2025 21:25 Post subject:
Going over router settings while reconfiguring is good ... You may stumble upon something.
At one time I decided to try the firewall setting Filter UDP floods with the default setting of 5 pkts/s. It didn't cause harm immediately and so I forgot about it, as these things go.
I don't know how that filter behaves in a more simple network setup, but I have a local PiHole server for DNS. DNS requests turn out to be UDP packets.
The filter apparently doesn't make a distinction between UDP from outside and from the LAN itself, like from the PiHole server.
Anyway, I think the UDP flood filter is what caused barrages of DNS requests from the PiHole. These subsided soon enough, but there were occasionally over a thousand DNS 'connections'.
Poor Raspberry Pi Zero W running PiHole ...
My habit of keeping tens of web pages open in a browser can only make it worse.
I am not saying this is the cause of the frequent restarts for which I reset the router and am reconfiguring it. I only just finished the first phase of that.
The networking page is still at default and I haven't created the VAP's yet, which I used to have for IoT and Guests. So far so good. Patience is a virtue.
Joined: 03 Nov 2015 Posts: 383 Location: Florida, USA
Posted: Sat Aug 09, 2025 23:23 Post subject: Re: R7800 and XR500 frequent random restarts
ArjenR49 wrote:
I don't know on which build it started to happen, but on all recent builds both routers restart one or more times within 24 hours.
Good to see a couple of gurus discussing this. What is recent ? as I have (2) R7800s on r61915 and I`m up 26 days on both. There is a recent thread about SFE that could be something. I agree with you on issues with settings. Mine are configured as per "msoengineers" WiFi sticky. He did a great job but this is almost 5yrs old and some settings are not there anymore and some new added. Something discussing filters, new firewall settings added, ect. would be such a big help. _________________ ......All GOOD here... Just Handshakes and Time Stamps !......
Joined: 05 Oct 2008 Posts: 850 Location: Helsinki, Finland / nr. Alkmaar, Netherlands
Posted: Sat Aug 09, 2025 23:58 Post subject:
Some time ago I used NSS-ECM, but then the advise became not to use it ... Perhaps when the switch tab went away and the networking GUI changed a lot. So, I haven't used any SFE recently.
I did notice a change in the GUI between the Services, services tab saved from build 61557 and the current 63036.
OLD:
DHCP Server Setup
Use JFFS2 for Client Lease DB (Not mounted)
Use NVRAM for Client Lease DB
Used Domain LAN & WLAN
LAN Domain mdnet
Additional Options
NEW:
DHCP Server Setup
Use JFFS2 for Client Lease DB (Not mounted)
Use NVRAM for Client Lease DB
Additional Options
So the two 'domain' settings are now gone. I hadn't noticed it, perhaps they disappeared with today's reconfiguration. It doesn't seem to matter in my setup.
In my network DHCP is provided by the router.
DNS by a local PiHole DNS server, which has a list of local DNS records including the LAN domain name.
Joined: 05 Oct 2008 Posts: 850 Location: Helsinki, Finland / nr. Alkmaar, Netherlands
Posted: Sun Aug 10, 2025 9:35 Post subject:
kernel-panic69 wrote:
Used domain and LAN domain settings were removed due to redundancy. The domain setting is now on the Basic Setup tab under WAN Setup -> Optional Settings and is now all-inclusive.
This is what I see under WAN Setup:
WAN Setup
WAN Connection Type
Connection Type
Ignore WAN DNS
Use VLAN Priority
Optional Settings
Router Name
Hostname
Domain Name
MTU
Shortcut Forwarding Engine
STP Enable Disable
The hostname and domain name are supposed to be supplied by the ISP:
Hostname:
Enter the hostname provided by your ISP.
Domain Name:
Enter the domain name provided by your ISP.
Surely this doesn't mean the local domain name that I chose myself like I entered in the now gone settings on the settings, settings tab. My ISP (cable provider) doesn't provide any hostname nor a domain name.
I'm a bit puzzled now.
Joined: 05 Oct 2008 Posts: 850 Location: Helsinki, Finland / nr. Alkmaar, Netherlands
Posted: Mon Aug 11, 2025 7:46 Post subject:
As the final step of totally reconfiguring the R7800 I set up a second bridge for LAN port #4 on the networking tab so as to have some servers on a separate wired network.
It didn't go as smoothly as the rest of the reconfiguring.
Among others the DHCP settings for two VAP's that I had set up earlier suddenly disappeared completely when I rebooted the router while working on the networking tab.
Bridge creation also didn't go as it used to go. At first the bridge setting that comes up as a list starting with VLAN Filtering showed only IGMP Snooping, no list. I had to do it several times over to get the settings for the new bridge to show and stick. The target was no STP and enabling only Linklocal Learn, as it used to be.
It may have required more saving and rebooting at the right moments along the way.
In the end I got it right and all done so I could start the 4 servers connected to LAN port #4 to this VLAN again.
I haven't seen spontaneous rebooting after that.
I now tend to think the reboots seen before reconfiguring had something or everything to do with the Filter UDP floods setting (at 5 pkts/s) interfering severely with the UDP traffic generated by my local DNS server on the LAN (PiHole with Unbound).
Later I found a remark made by Brainslayer from earlier this year that he had unintentionally made the UDP flood filter to work on both inside and outside UDP traffic and that he would shortly correct this. It looks to me this has not happened yet.
Joined: 16 Nov 2015 Posts: 7065 Location: UK, London, just across the river..
Posted: Mon Aug 11, 2025 9:48 Post subject:
Yep if you dont understand those options and know how to use it..dont use it...its a general rule...
I do not recommend using those new options, unless you need it for a testing or specific use...only ! _________________ Atheros
TP-Link WR1043NDv2 -DD-WRT 62606 Gateway/DoT,Forced DNS,Ad-Block,Firewall,x4VLAN,VPN
TP-Link WR1043NDv2 -Gargoyle OS 1.15.x AP,DNS,QoS,Quotas
Qualcomm-Atheros
Netgear XR500 -DD-WRT 63257 GTW/SmDNS/DoT,AD-Blk,Forced DNS,AP&Net Isolation,x2VLAN,Vanilla
Netgear R7800 --DD-WRT 62606 Gateway/DNSCryptv2,AD-Block,Forced DNS,AP&Net Isolation,x3VLAN,Firewall,Vanilla,VPN cli
Netgear R9000 --DD-WRT 62606 Gateway/DoT,AD-Block,AP Isolation,Firewall,Forced DNS,x2VLAN,Vanilla
Dynalink DL-WRX36-DDWRT 62606
Broadcom
Netgear R7000 --DD-WRT 63257 GTW/DNScrypt-proxy2/AD-Block,IPset Firewall,Forced DNS,x4VLAN,VPN cli
NOT USING 5Ghz ANYWHERE
------------------------------------------------------
Stubby DNS over TLS I DNSCrypt v2 by mac913
Joined: 05 Oct 2008 Posts: 850 Location: Helsinki, Finland / nr. Alkmaar, Netherlands
Posted: Tue Aug 12, 2025 0:00 Post subject:
Alozaros wrote:
Yep if you dont understand those options and know how to use it..dont use it...its a general rule...
I do not recommend using those new options, unless you need it for a testing or specific use...only !
I think it wasn’t illogical to assume that filtering certain traffic would be directed at traffic from outside, not from inside the LAN.
I hadn’t seen Brainslayer’s comment at the time I enabled the UDP Flood filter, but IMO it confirms that my assumption wasn’t so much out of line.
Perhaps BS forgot about it, since it looks like that it hasn’t been corrected yet.
That said, I must admit that the router is inside a CG network, so the chance of UDP floods being directed at it from the internet are likely low, so yes it wasn’t a very useful option in this case.
OLD:
DHCP Server Setup
Use JFFS2 for Client Lease DB (Not mounted)
Use NVRAM for Client Lease DB
Used Domain LAN & WLAN
LAN Domain mdnet
Additional Options
NEW:
DHCP Server Setup
Use JFFS2 for Client Lease DB (Not mounted)
Use NVRAM for Client Lease DB
Additional Options
So the two 'domain' settings are now gone.
The setting is not showing/available in the GUI, but you can still set them in CLI.
If you enter a domain name under WAN SETUP you are only setting the domain for the WAN interface not the LAN. If your ISP expects a certain domain you my not be able to connect until you correct the domain.
To see the results first hand try this.
--Enter a domain in the WAN SETUP area such as bedrock.net click save & apply.
--Now start a SSH session and type these commands:
Code:
nvram get wan_domain
nvram get lan_domain
You will see the domain you entered in the GUI is only listed in the wan_domain value, not in the lan_domain.
If you need to set a domain for the your local area network(lan)
you will have to do so using the CLI by using these commands: {example: bedrock.net}
Code:
nvram set lan_domain=bedrock.net
nvram commit
Then to remove a domain from the LAN you simply issue the same commands above but do not enter anything after the '=' sign or use empty single quotes '' Then commit the change.
Code:
nvram set lan_domain=
---OR---
nvram set lan_domain=''
Note: If you DO NOT issue NVRAM COMMIT the changes you made are only in ACTIVE memory and will not persist after reboot.
Joined: 05 Oct 2008 Posts: 850 Location: Helsinki, Finland / nr. Alkmaar, Netherlands
Posted: Thu Aug 14, 2025 13:32 Post subject:
OneDumDuk wrote:
ArjenR49 wrote:
OLD:
DHCP Server Setup
Use JFFS2 for Client Lease DB (Not mounted)
Use NVRAM for Client Lease DB
Used Domain LAN & WLAN
LAN Domain mdnet
Additional Options
NEW:
DHCP Server Setup
Use JFFS2 for Client Lease DB (Not mounted)
Use NVRAM for Client Lease DB
Additional Options
So the two 'domain' settings are now gone.
The setting is not showing/available in the GUI, but you can still set them in CLI.
If you enter a domain name under WAN SETUP you are only setting the domain for the WAN interface not the LAN. If your ISP expects a certain domain you my not be able to connect until you correct the domain.
To see the results first hand try this.
--Enter a domain in the WAN SETUP area such as bedrock.net click save & apply.
--Now start a SSH session and type these commands:
Code:
nvram get wan_domain
nvram get lan_domain
You will see the domain you entered in the GUI is only listed in the wan_domain value, not in the lan_domain.
If you need to set a domain for the your local area network(lan)
you will have to do so using the CLI by using these commands: {example: bedrock.net}
Code:
nvram set lan_domain=bedrock.net
nvram commit
Then to remove a domain from the LAN you simply issue the same commands above but do not enter anything after the '=' sign or use empty single quotes '' Then commit the change.
Code:
nvram set lan_domain=
---OR---
nvram set lan_domain=''
Note: If you DO NOT issue NVRAM COMMIT the changes you made are only in ACTIVE memory and will not persist after reboot.
This is a very helpful answer and I was kind of sure the settings on the Basic setup page are for a different purpose. No ISP that I have encountered ever required a certain domain name to be set for WAN.
Perhaps the setting for LAN domain is not really necessary.
I have a PiHole server and it also has a domain setting of itself.
DIG requests for local names on my work station work even though currently the LAN_domain is unset.
I'll remove the wan_domain. It's not needed in my case.
