DHCP broken over MAC bridge miniport adapter in Win7

Windows Network Bridging Utility

Status: Beta

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DHCP broken over MAC bridge miniport adapter in Win7

Forum: General Discussion

Created: 2015-03-25

Updated: 2015-04-10

lm1 - 2015-03-25

I'm bridging Ethernet segment with virtual WiFi AP and everything works great except for DHCP.
I have DHCP server on the Ethernet side but all devices on WiFi side get the same IP.

I have found that somehow not only the MAC address in the Ethernet header is modified by the bridge but also the requester MAC inside DHCP payload gets modified as well causing a bogus response.
Looks like Win7 MAC bridge miniport specifically modifies DHCP packets this way braking DHCP entirely.
Has someone noticed this as well? Perhaps there is a way to fix that or a replacement bridging driver is available?

At this point I run standalone DHCP server on the Win7 box so DHCP traffic does not pass the bridge at all avoiding the issue.

Last edit: lm1 2015-03-25

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Benjamin Kalytta - 2015-04-10

In order to be able to use DHCP you have to run a dedicated DHCP server. WiFI AP has it's own DHCP (192.168.173.1...254), but as soon as it get bridged this DHCP server is deactivated, so only link local addresses are available.

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