Hello,
After doing certain activities, in my case, restoring an external SD card from a backup using a program, watchdog thinks that
"device eth0 did not receive anything since last check"
which triggers a reboot as I've configured in Watchdog.
However, eth0 is working fine, /proc/net/dev is incrementing, the interface is working, I'm serving HTTPS/HTTPS/DNS over this interface, I'm SShed in on the interface.
/dev/proc/net is incrementing, I am cat'ing it and watch it increment AS watchdog says its not receiving anything

Relevant links:
https://github.com/RPi-Distro/repo/issues/237#issuecomment-1490751380

Sorry, this is a duplicate of #1033716

I think the problem is that the '/proc/net/dev' command returns 'unsigned
long long' (see here:
https://github.com/raspberrypi/linux/blame/rpi-6.1.y/net/core/net-procfs.c#L82),
but the watchdog 'iface.c' code uses 'unsigned long', which causes the
'bytes' to always be 4294967295 (0xFFFF FFFF or ULONG_MAX). There is no
check that the 'strtoul' operation has been successful.

Recompiling the watchdog using 'unsigned long long' for 'bytes' and
changing 'strtoul' to 'stroull' apparently solved the problem for me after
doing a quick test. See changes below:

diff --git a/iface.c.orig b/iface.c
index 5db4e55..7b5eba6 100644
--- a/iface.c.orig
+++ b/iface.c
@@ -41,11 +41,11 @@ int check_iface(struct list *dev)

                        for (; line[i] == ' ' || line[i] == '\t'; i++) ;
                        if (strncmp(line + i, dev->name, strlen(dev->name))
== 0) {
-                               unsigned long bytes = strtoul(line + i +
strlen(dev->name) + 1, NULL, 10);
+                               unsigned long long bytes = strtoull(line +
i + strlen(dev->name) + 1, NULL, 10);

                                /* do verbose logging */
                                if (verbose && logtick && ticker == 1)
-                                       log_message(LOG_DEBUG, "device %s
received %lu bytes", dev->name, bytes);
+                                       log_message(LOG_DEBUG, "device %s
received %llu bytes", dev->name, bytes);

                                if (dev->parameter.iface.bytes == bytes) {
                                        fclose(file);


diff --git a/extern.h b/extern.h.orig
index 2eccf0b..81bc620 100644
--- a/extern.h
+++ b/extern.h.orig
@@ -30,7 +30,7 @@ struct filemode {
 };

 struct ifmode {
-       unsigned long long bytes;
+       unsigned long bytes;
 };

 struct tempmode {

Let me know what you think.

- Cezar Chirila