Problem: L2 Broadcasts not arriving at DHCP Server

Ingo S

Renowned Member
Oct 16, 2016
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Hi all

Lately i've been struggling with our DHCP Server.
I'm running an isc-dhcp server on a debian VM. This VM has a network interface on vlan 104 (user net) and on vlan 101 (server net). Communication on vlan 104 is working, to all devices on vlan 104 (ping) without issues.
BUT if my PC, or really any other device on VLAN 104, sends a L2 Broadcast DHCP Discover, the DHCP Server doesn't get it. I checked with tcpdump. Packet goes out of my PC, but it does not arrive at the vlan 104 interface on the DHCP Server. Ping etc works just fine...

This is my PVE config for the DHCP Server:
1720084464995.png
This is the PVE Hosts Network config:
1720084521995.png
This is the DHCP VM Network Config
1720084604746.png
 

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