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Vigor2862 periodically drops all LAN connectivity

  • metlex
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01 Oct 2022 16:52 #101836 by metlex
Hello Folks,

I've been using a Vigor2862 as my home router for a couple of years now and I've noticed that (with apparently increasing frequency) all LAN connectivity for devices connected to it drops for a period of 2-5 minutes. It seems to recover on its own within a few minutes, or with a reboot of the router itself.

It doesn't seem to matter how devices are connected (WiFi/via Desktop switch/Direct to router) so it would seem that the Draytek is the point of failure.

Wireshark capture taken on my local machine during one of these periods shows almost nothing on the wire besides a few ARP requests from desktop switches and nothing at all from the router. I haven't noticed anything immediately obvious/weird during PCAPs right before/during/after the issue occurs (apart from a total loss of all LAN connectivity of course!) Ping to any device on the LAN or the router itself fails during this period.

I captured a syslog to USB drive from the router itself overlapping one of these periods, but there's not a lot of useful info in it to my eyes. WAN related messaging looks the same as it does during a healthy period and according to the router remains up - but it's like the LAN just ceased to exist for the duration.

Nothing special in the router configuration either - it's pretty simple/largely out of the box stuff.

There's nothing I'd consider particularly special about my local network, but a rough list of devices is:

  • Ubiquiti UniFi APs x2 on PoE
    2 x unmanaged desktop switches
    Various Amazon IOT/Fire Stick devices
    Phones/PCs/Tablets


System Information
Model Name: Vigor2862
Firmware Version: 3.9.8.1_BT
Build Date/Time: Apr 26 2022 13:25:44
DSL Version: 779517_A/B/C HW: A

Happy to provide anything else that might be useful from a diagnostic perspective.

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02 Oct 2022 20:06 #101839 by hornbyp

metlex wrote:
Wireshark capture taken on my local machine during one of these periods shows almost nothing on the wire besides a few ARP requests from desktop switches and nothing at all from the router.



It could be some other device on another LAN port that's upsetting it. You could use a PC running Wireshark on a 'mirror' port to examine all the LAN traffic...


Nothing special in the router configuration either - it's pretty simple/largely out of the box stuff.


In that case, it's well worth a Factory Reset and start again. (There are various levels of 'start again', ranging from type-it-all-back-in, to restoring config. files (either for the Router as a whole, or for individual functions).

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03 Oct 2022 19:11 #101843 by doctordray
Having the same problem with a Vigor2860 since putting on the latest firmware 3.9.2 BT.

Have just factory reset it and redone the config from hand (PAINFUL as there was quite a lot of it).

Will report back here if it starts throwing its toys out of the pram again. Was happening pretty frequently, every few hours, so should know by tomorrow if it's solved.

BTW @Metlex the 3.9.2 release is CRITICAL and fixes CVE-2022-32548 and CVE-2022-0778 so you might want to update to it yourself. Although it may be less stable than what you've got, who knows! Fingers crossed the ground zero approach has paid dividends.

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