But it is ICS, because when I kill those two services (host network service, and subsequently ICS), then I am able to use the new BootP.
Then I wonder what connection is being shared?
I did some more poking around.
Initially, the ICS process was not bound to UDP port :67, or any ports for that matter, according to [netstat -ano].
After I checked the box above and selected the WiFi network as the "private network connection," the ICS process (ID 3436) was connected to some apparently random ports on localhost:
UDP 0.0.0.0:49152 *:* 3436
UDP 127.0.0.1:49153 *:* 3436
Then, I turned on the Wi-Fi device and connected to my access point (IP address 192.168.1.137). At that point, the ICS process bound to several UDP ports, including :67 on IP address
.137, which makes sense:
UDP 0.0.0.0:53 *:* 3436
UDP 0.0.0.0:53 *:* 3436
UDP 0.0.0.0:49152 *:* 3436
UDP 0.0.0.0:51916 *:* 3436
UDP 0.0.0.0:51918 *:* 3436
UDP 0.0.0.0:64879 *:* 3436
UDP 127.0.0.1:49153 *:* 3436
UDP 192.168.137.1:67 *:* 3436
UDP 192.168.137.1:68 *:* 3436
UDP [::]:547 *:* 3436
UDP [::]:51917 *:* 3436
UDP [::]:51919 *:* 3436
UDP [::]:64880 *:* 3436
UDP [fe80::41e9:f0d3:c102:5439%14]:53 *:* 3436
And the Rockwell BootP-DHCP tool was not able to run because UDP port :67 was taken, even though I selected the
non-Wi-Fi adapter at 192.168.1
.193, although that is the same subnet*.
Then, I disconnected from the Wi-Fi access point, and even turned the Wi-Fi device off, so the .137 IP interface was not even up and running, and still ICS was listening on UDP port :67 and keeping the BootP-DHCP tool from connecting to the .193 IP interface.
Finally, I restarted Host Network Service and ICS, ICS got a new process ID (13132), and that new process went back to using similar ports to the original case:
UDP 0.0.0.0:53 *:* 13132
UDP 0.0.0.0:57438 *:* 13132
UDP 0.0.0.0:57439 *:* 13132
but not UDP port :67, and stayed that way even after I disabled the ICS in the adapter Properties=>Sharing dialog, and the BootP-DHCP tool was able to run again.
* I repeated the test after assigning the static IP 192.168.137.1 to the Wi-Fi on subnet 192.168.137.0/24, in order to use a different subnet. However, the results were the same i.e. the Rockwell BootP-DHCP Tool could not listen to UDP port :67 on the Ethernet 192.168.1.193 interface while ICS was sharing to private network 192.168.137.0/24 until the Wi-Fi 192.168.137.1 interface was disconnected and the ICS process restarted.