I have excatly the same issue as you, regular reboots. sometimes the router is up for 100+hours and others its less than 24h

I have a Vigor2860n+ running a beta firmware 3.8.9.8_RC2_BT som far support has suggested it a issue with

ipv6
5Ghz wifi
mtu reduced to 1492

I have now disabled ipv6, disabled wireless 2.4 and 5Ghz and changed the mtu along with the beta firmware

My syslog to usb does not work but i have debug dumps

Router Model: Vigor2860n+ Version: 3.8.9.8_RC2_BT English
Profile version: 3.0.0 Status: 1 (0x482a57ec)
Router IP: 192.168.0.1 Netmask: 255.255.255.0
Firmware Build Date/Time: Jun 2 2020 23:18:41
Router Name: DrayTek
Revision: 90875 V389_2860
Current VDSL2 Firmware Version: 05-07-06-0D-01-07
ADSL Firmware Version: 05-07-02-08-00-01 Annex A
VDSL2 Firmware Version: 05-07-06-0D-01-07

---

firmware exception debug info

---

EPC=1100fc03, Cause=816b1e94, Status=1100fc03, BadAddr=00000000, RetAddr=80bcf60c
exception id=5(ADES: Address Error Store)
exception occured in IdleTask Timeout
task_id=110, SP=0x816bc4f8(4572 bytes free, 128 used bytes)
system tick =702
CURRENT_VERSION : 3.8.9.8_R
get from address : 80004000
Dump CPU registers:

---

$ 0: 00000000 fffffffe 00000010 00101000
$ 4: be100000 000000ff 00000008 0000000a
$ 8: 0000000d 5f726573 0a7c5ac5 64282921
$12: 0000000f 816bc1e0 80ed0178 ffffffff
$16: 835f3e60 00000007 82ea2870 00000000
$20: 00000000 816bc8c4 00000000 816bc578
$24: 00000001 00009e00 00000000 00000000
$28: 816bc000 816bc4f8 00000003 80bcf60c
List a possible caller functions:

---

func( 0)=8002c4dc
func( 1)=80a70140
func( 2)=80ed0178
func( 3)=80a8ba78
DrayTek>




08/07/20


DrayTek> sys ver dbg

---

firmware exception debug info

---

EPC=809ccd94, Cause=00800010, Status=1100fc02, BadAddr=82f20000, RetAddr=809ccd3c
exception id=4(ADEL: Address error Load)
exception occured in TASK Lavel
task_id=161, SP=0x816ceb08(4094 bytes free, 2040 used bytes)
system tick =11403699
CURRENT_VERSION : 3.8.9.8_R
get from address : 80004000
Dump CPU registers:

---

$ 0: 00000000 fffffffe 8366a2a2 83a3a750
$ 4: 83a3a750 83a3a750 83669d4a 00000558
$ 8: 837c4d00 80a94420 00000002 1100fc00
$12: 81adead0 345f70fb 81bc0bec 00000000
$16: 00000550 00000002 00000002 00000004
$20: 82f1b4f4 82f20000 00f00055 82f1be5c
$24: 00000002 00000000 00000000 00000002
$28: 8161f000 816ceb08 40000000 809ccd3c
List a possible caller functions:

---

func( 0)=80a7bafc
func( 1)=809a89f0
func( 2)=8009352c
List backtrace functions:

---

func( 0)=809ccd94
func( 1)=80a7bafc
func( 2)=809a89f0
func( 3)=8009352c

I have found a solution, but the not the one we all hoped for.

Backstory
Our house always had intermittent problems with various wireless devices on our network, but I could never quite pinpoint what it was. Cue the COVID-19 lockdown and I find myself in conference meetings for hours over wifi from my new home office (cardboard on the floor to protect the carpet, a desk from COSTCO, two old monitors and a Netgear AC1200 access point to work as a bridge to avoid trailing a cable through the house). What I discover over the course of several weeks is that the problem we have been having isn't any of the wifi devices, or the channel that we have chosen for the wifi, or any of our settings, but is the wifi services on our beloved Vigor2862. The 5Ghz was normally quite stable, but sometimes would go offline for hours on end. Then the 2.4Ghz was more stable, but would sometimes drop too. There were even times when the 2.4Ghz would drop, the 5Ghz would reappear for two seconds, disappear, and then the 2.4Ghz would start again like some kind of switcheroo, but I have always had Band Steering disabled so I have no idea what was going on there. Once the 5Ghz went down as I was in the Draytek dashboard, but disabling and re-enabling the wifi did nothing, only restarting the router. Then there were times when the 5Ghz was up, but I was still unable to connect to it. This needed to be fixed as I was intermittently disconnected from several meetings. Thankfully the Netgear access point would connect to whichever wifi was running at the time so I simply needed to wait for either the 2.4Ghz or 5Ghz to reappear to be reconnected. This was typically a couple of seconds, but wasn’t ideal and now knowing the source of the problem, it was time to resolve the issue.

Considered solution
I was going to purchase a VigorAP 903 and a VigorAP 802 to create a mesh network, but there were two problems with that.
1) I didn't like the idea of rewarding Draytek with more money through not fixing a software problem.
2) I discovered many reviews of both devices had people complaining of the same issues I was experiencing with my Vigor2862.[/list]

Solution
I have purchased, installed and used for several weeks now, without any problems, three TP-LINK Deco M9 Plus wireless access points and they are amazing. I haven't had a single problem and the transfer speeds between the access points (because of the third 5Ghz inter access point back channel) are really fast and stable (I am seeing 30.4MB/s sustained sending and 19.8MB/s sustained receiving). So not the solution I wanted (an updated DrayOs firmware) but I am very happy with this new setup, and I haven't been dropped from any meetings. We are still using the wonderful (but now with a slightly tarnished reputation in our house) Vigor2862, but with the wifi disabled. And now I need to find a use for a spare Netgear access point.

What version firmware are you on? Mine still crashes with the wifi disabled.

Decompiled wrote:
I have found a solution, but the not the one we all hoped for.

Backstory


Considered solution
I was going to purchase a VigorAP 903 and a VigorAP 802 to create a mesh network, but there were two problems with that.
1) I didn't like the idea of rewarding Draytek with more money through not fixing a software problem.
2) I discovered many reviews of both devices had people complaining of the same issues I was experiencing with my Vigor2862.[/list]

Solution
I have purchased, installed and used for several weeks now, without any problems, three TP-LINK Deco M9 Plus wireless access points and they are amazing. I haven't had a single problem and the transfer speeds between the access points (because of the third 5Ghz inter access point back channel) are really fast and stable (I am seeing 30.4MB/s sustained sending and 19.8MB/s sustained receiving). So not the solution I wanted (an updated DrayOs firmware) but I am very happy with this new setup, and I haven't been dropped from any meetings. We are still using the wonderful (but now with a slightly tarnished reputation in our house) Vigor2862, but with the wifi disabled. And now I need to find a use for a spare Netgear access point.

Currently 3.9.1.3_BT. Perfectly stable, although I do have a weekly scheduled restart.

Mucka wrote:
What version firmware are you on? Mine still crashes with the wifi disabled.

Decompiled wrote:
I have found a solution, but the not the one we all hoped for.

Backstory


Considered solution
I was going to purchase a VigorAP 903 and a VigorAP 802 to create a mesh network, but there were two problems with that.
1) I didn't like the idea of rewarding Draytek with more money through not fixing a software problem.
2) I discovered many reviews of both devices had people complaining of the same issues I was experiencing with my Vigor2862.[/list]

Solution
I have purchased, installed and used for several weeks now, without any problems, three TP-LINK Deco M9 Plus wireless access points and they are amazing. I haven't had a single problem and the transfer speeds between the access points (because of the third 5Ghz inter access point back channel) are really fast and stable (I am seeing 30.4MB/s sustained sending and 19.8MB/s sustained receiving). So not the solution I wanted (an updated DrayOs firmware) but I am very happy with this new setup, and I haven't been dropped from any meetings. We are still using the wonderful (but now with a slightly tarnished reputation in our house) Vigor2862, but with the wifi disabled. And now I need to find a use for a spare Netgear access point.