I'm seeing strange DHCP behavior between Android and Windows and wanted to see if anyone here could make sense of it. It seems like Android is spamming a dozen or so discovers in a second, and ignoring anything the server says until the lease renewal time is up (from a prior connection). https://www.cloudshark.org/captures/e6dcb03e4e03 EDIT: There are comments attached to the capture. asked 02 Sep '15, 09:22  lordbah edited 03 Sep '15, 08:19 |
One Answer:
The DHCP server responses are broadcast, while the client asks for unicast responses. Therefore the responses don't seem to arrive. answered 04 Sep '15, 03:52  Jaap ♦ |
So that means Windows 7 ICS DHCP server isn't honoring the unicast flag. Well, it is only a SHOULD in the standard, right?
Sometimes Android does see the response even though it is broadcast.
There are a number of hits on setting this flag on Windows as a DHCP client. Nothing I can find about it with Windows as DHCP server. I'm interested to hear of workarounds - arcane registry settings or whatever that would cause Windows to unicast.
Windows Firewall has a setting "Allow unicast response to multicast or broadcast network traffic", but is set to Yes in all profiles so it shouldn't be causing this. (Action/Properties/Settings/Customize)