[Solved] Network crashes so I lose both interfaces

[thegrind]

I am running Gentoo on a Rpi5+. I followed the gentoo wiki to install gentoo on the microSD so I am using the pre-built kernel and I am using the firmware from the git shown on the wiki. I did the installation about three weeks ago (sept 20th). I have bluetooth, I am using the wifi, and I am using the ethernet cable. I set a higher priority for wlan0 since it is faster for me as my wall plug adapter isn't high speed. I am using NetworkManager that I emerged. My uname -a is 6.6.50-v8-16k+ #1795 SMP PREEMPT Tue Sep 10 19:41:02 BST 2024 aarch64 GNU/Linux. I am running headless. I am using openrc.

I had this issue on my previous distro (Arch) where i would completely lose my network connections so I lost my ssh connectiion which means a hard reboot. It was happening randomly. Sometimes after a half day sometimes after a week. I hooked the ethernet cable thinking it was wifi that was crashing. For arch I was using systemd-networkd with wpa_supplicant.

I am still seeing the same issue on gentoo but now I am using networkmanager. I am hoping to find a solution to this as this is the only issue I've been having since I bought the Rpi5. I don't know if it is firmware as I can just pull the latest ifrmware and move it over and this will fix my issue.

[gentoo_ram]

My setup is totally different so I can't give direct advice (OpenRC, 6.11 kernel, use iwd for Wifi, etc). I haven't seen the symptom where all my networking goes away at once. I run ethernet and Wifi simultaneously without issue.

But I will say I had difficulties running a kernel with the 16k page size. At least in kernel 6.9.x and 6.10.x I know that the 16k page size was not compatible with the ZRAM feature. When I used ZRAM devices on a 16k-page kernel my RPi5 would eventually lock up and die. When I turned off ZRAM all my problems went away. I went back to the 4k page kernel because I really wanted to use the ZRAM feature. I don't have issues with the 4k page kernel. (6.11.1-v8+ #20 SMP PREEMPT)

Given that experience I would try using a kernel with a more common 4k page size (the kernel will be labeled v8+ instead of v8-16k+). Try that a while and see if you still have problems. Changing the kernel should be transparent to the rest of the system; although you'd have to reinitialize any swap space you might have.

[thegrind]

Thanks for the help. I am not using Zram as my system is for kodi and I figure 8GB is enough. I am not seeing a total lockup as the I can control kodi with my remote (CEC). How did you get a 6.11 kernel. The Rpi github link takes me o kernel 6.6.

[Banana]

No solution here, rather some ideas:

Is the ethernet cable all the time connected so it could be a decision problem what interface to use? So try it only with one interface active at once.

Do you have configured the same IP address to both interfaces? Try using different IPs

[gentoo_ram]

I get a 6.11 kernel by building it on my own. Do a 'git clone https://github.com/raspberrypi/linux.git'. That will get you the Raspberry Pi Linux kernel source repository. Then check out whatever branch you want. I'm currently using the rpi-6.11.y branch. Start with 'make bcm2712_defconfig' then go from there configuring in whatever kernel parameters you want.

I don't have issues with multiple IP interfaces. I'm using iwd to mange my Wifi link; found it easier to configure and deal with than wpa_supplicant. I even had an issue once where my ethernet switch went into some weird failure state but my Wifi link stayed up.

Code: Select all

$ ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 brd 127.255.255.255 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host proto kernel_lo 
       valid_lft forever preferred_lft forever
2: end0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether d8:3a:dd:f3:d3:81 brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.81/24 brd 192.168.1.255 scope global dynamic noprefixroute end0
       valid_lft 59940sec preferred_lft 45196sec
    inet6 2603:8001:xxxx:5680:291c:2d6c:6a09:7f8e/64 scope global dynamic mngtmpaddr noprefixroute 
       valid_lft 362042sec preferred_lft 362042sec
    inet6 fe80::734c:51a3:6842:2f9/64 scope link 
       valid_lft forever preferred_lft forever
3: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether d8:3a:dd:f3:d3:82 brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.83/24 brd 192.168.1.255 scope global dynamic noprefixroute wlan0
       valid_lft 60950sec preferred_lft 46635sec
    inet6 2603:8001:xxxx:5680:491d:789e:987d:228b/64 scope global dynamic mngtmpaddr noprefixroute 
       valid_lft 362042sec preferred_lft 362042sec
    inet6 fe80::9d9e:e307:308e:a953/64 scope link 
       valid_lft forever preferred_lft forever
$ ip r
default via 192.168.1.1 dev end0 proto dhcp src 192.168.1.81 metric 2 
default via 192.168.1.1 dev wlan0 proto dhcp src 192.168.1.83 metric 3 
192.168.1.0/24 dev end0 proto dhcp scope link src 192.168.1.81 metric 2 
192.168.1.0/24 dev wlan0 proto dhcp scope link src 192.168.1.83 metric 3 
$ iwconfig
wlan0     IEEE 802.11  ESSID:"xxxxx"  
          Mode:Managed  Frequency:5.785 GHz  Access Point: D8:EC:5E:E9:58:7A   
          Bit Rate=24 Mb/s   Tx-Power=0 dBm   
          Retry short limit:7   RTS thr:off   Fragment thr:off
          Power Management:on
          Link Quality=70/70  Signal level=-29 dBm  
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:58  Invalid misc:0   Missed beacon:0

[thegrind]

I still can't figure out why my RPI5 drops my wifi. I have tried netrc, networkmanager, iwd, and wpa_supplicant. I ended up compiling kernel 6.11. I leave my eth0 unplugged. I am now just using iwd and dhcpcd. Like the other three sometimes I can go only go a half of a day and sometimes it will work for a week. With iwd, when it drops my internet, I can plug my eth0 cable in and I get eth0 and wlan0 but if I unplug eth0 then I will lose eth0 (naturally) and wlan0 as well. I never had these issues with Rpi3 and my other devices. I am using OPenRC. I installed metalog but I don't see anything in the logs but I am just using the default settings. Dmesg shows nothing unusual either.

[thegrind]

I think I may have figured it out finally.

I just happen to look at LFS for a Rpi and they said you need to add a file to keep memory available for the network or it will crash networking if I run out of RAM (I probably have some memory leaks with Kodi apps).

Created a /etc/sysctl.conf

and added

vm.min_free_kbytes=8192

10 days without losing my network connection so far. I will mark solved after a few more days.

5/19/2025 - Has been 24 days now.