If running in DHCP or BOOTP mode, the stack shall be able to restart the DHCP/BOOTP state machine if all Ethernet links were gone and new link is being established

If running in DHCP or BOOTP mode, the stack shall be able to restart the DHCP/BOOTP state machnine if all Ethernet links were gone and a new link habs been established.
Currently such a behavior is not supported. If the link was gone and comes back again, the stack just continues using the IP address without re-checking whether the IP address it received from the DHCP/BOOTP server can still be used.

This requiremend comes from the EtherNet/IP specification Volume 2 Edition 1.21, chapter 5-4.7 "Behavior" (TCP/IP Object).