Watchdog reset when arduino hangs longer than 5 minutes

CrazyVito11:
I'll set the watchdog timer to 1 second...

But i do have one question, can the interrupt break the code while it is for example doing a traceroute?

#define PING_TIMEOUT 5000

So that would be at the most six interrupts during the ping timeout period.

~50 machine instrutions / 16000000 instructions per second * 1000000 microseconds per second = ~4µs per interrupt

Over the timeout period the processor will spend ~24µs in the interrupt service routine. That comes out to 4.8e-7% of the processor time spent servicing the interrupt and 99.99999952% of the processor time available for other things like handling the traceroute.

I'm going with "no".