udhcpc: udhcpc not stopping due to Ethernet power down

[Bryan Evenson]

All,

I'm seeing an odd issue with udhcpc and I'm trying to determine if I don't have the command line options set correctly or if its due to how udhcpc operates.  I have a system that is using BusyBox version 1.24.1, and I'm using udhcpc for its wired Ethernet port.  The startup script is calling udhcpc as follows:

	udhcpc -R -b -p /var/run/udhcpc.eth0.pid -i eth0

I've been having some networking issues with this device, and I found out that the cable modem its connected to is set to power down the Ethernet connection after two minutes with no traffic.  I do have something a task that uses the network every four minutes, but nothing is guaranteed to operate more frequently than that.  When I finally logged onto my device, I found out that there were about 100 instances of udhcpc up and running.  I believe each time the Ethernet port is enabled udhcpc starts back up again, but for some reason the old instance of udhcpc keeps running.

Has anyone else seen this behaivor before?  Is it possibly related to this fix: https://git.busybox.net/busybox/commit/?h=1_28_stable&id=39bf15ba3e5d5a0f04eab05d4675241961bb333d?  Unfortunately I don't have a good way of updating Busybox on this system right now to test if upgrading to a more recent version fixes the issue.

Thanks,
Bryan