Wifi 5/6 dropped randomly if ipv6 is enabled - Bug dhcp6!!!

[Linuxonlinehelp_de]

Updated: 19.12.2022
#####################

Hi Support

at startup of analysis:
Wifi5/6 dropped randomly if ipv6 is enabled/disabled on gnome-network-manager-gui no Error on Logs! No red Kernel Messages.

My Lab:
At my Lab i disabled all ipv6 on my Subnet LAN Openwrt-Routers, and my Laptop loses "randomly" 20times a day the Internet but the Signal is 100% to the WIFI-Routers, no ping, no nslookup to first DSL-WAN Router possible.

First Handling:
After i manual enable/disable WIFI by switch is works again fast.

Analysis:
After some search on Net i disabled ipv6 in sysctl.conf !

GTK-Apps Affected: seen on network-manager/network-manager-gnome/wicd Managers

Hardware Change/Test:
I tested / changed 3 different old wifi-5+ new wifi-6 intel AX 7260 HMW mini-pci-cards same problem!

Now testing again..

Thanks
Linuxonlinehelp_eu

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: network-manager 1.10.6-2ubuntu1.4
ProcVersionSignature: Ubuntu 5.4.0-135.152~18.04.2-generic 5.4.212
Uname: Linux 5.4.0-135-generic x86_64
NonfreeKernelModules: wl
ApportVersion: 2.20.9-0ubuntu7.28
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Sun Dec 18 11:24:20 2022
IfupdownConfig:
 # interfaces(5) file used by ifup(8) and ifdown(8)
 auto lo
 iface lo inet loopback
InstallationDate: Installed on 2021-08-19 (486 days ago)
InstallationMedia: Ubuntu 18.04.3 LTS "Bionic Beaver" - Release amd64 (20190805)
IpRoute:
 default via 192.168.71.1 dev wlp3s0b1 proto dhcp metric 600
 169.254.0.0/16 dev wlp3s0b1 scope link metric 1000
 192.168.71.0/24 dev wlp3s0b1 proto kernel scope link src 192.168.71.123 metric 600
NetworkManager.state:
 [main]
 NetworkingEnabled=true
 WirelessEnabled=true
 WWANEnabled=true
SourcePackage: network-manager
UpgradeStatus: No upgrade log present (probably fresh install)
WifiSyslog:

http_proxy: http://127.0.0.1:8118/
modified.conffile..etc.NetworkManager.conf.d.default-wifi-powersave-on.conf:
 [connection]
 wifi.powersave = 2
mtime.conffile..etc.NetworkManager.conf.d.default-wifi-powersave-on.conf: 2022-06-30T19:17:37.737049
nmcli-dev:
 DEVICE TYPE STATE DBUS-PATH CONNECTION CON-UUID CON-PATH
 wlp3s0b1 wifi connected /org/freedesktop/NetworkManager/Devices/3 AXWIFI71 bec4545b-24e6-40ef-a933-43121b9b819b /org/freedesktop/NetworkManager/ActiveConnection/3
 enp2s0 ethernet unavailable /org/freedesktop/NetworkManager/Devices/2 -- -- --
 lo loopback unmanaged /org/freedesktop/NetworkManager/Devices/1 -- -- --
nmcli-nm:
 RUNNING VERSION STATE STARTUP CONNECTIVITY NETWORKING WIFI-HW WIFI WWAN-HW WWAN
 running 1.10.6 connected started full enabled enabled enabled enabled enabled
no_proxy:

[Linuxonlinehelp_de (linuxhelp)]

Disable ipv6 on sysctl.conf seems to fix the problem

Found a lot of dhcpd6 client problems on net with

the problem of randomly disconnects and problems to

new register/pull/expire time on ipv6 handling data from Routers.

This must be fixed! Network is a must have!

[Martin-Éric Racine (q-funk)]

Exactly what was the point of marking this bug as afecting all packages that handles network configuration?

[Linuxonlinehelp_de (linuxhelp)]

I could not determine exactly which part was having the problems, seems to me the dhcp client package or API to network-managers.

To this ubuntu develop/changes much on parts the network management handling ubuntu go other ways than other Debian/Linux OS.

If Company's disable IPV6 on local LAN for easy Firewall-Security-Handling, they will run into problems.
I know IPv6 should be implemented but on small Areas it makes less sense.

Users have still Problems on "easy" managing IPv6. They wont use small Routers to route local devices to the Internernet Provider's IPv6-DHCP Servers.

[Martin-Éric Racine (q-funk)]

I really need to ask:

Have you narrowed down which package causes the issue? If yes, can you please un-tag packages that are unrelated to the issue?

If you're just generally commenting on the relevance of enabling IPv6 on standard Ubuntu installations, tagging all packages that perform network configuration is the wrong approach.