Dropping reply received on <downstream interface> when using -iu/-id

[Patrick Cervicek]

> I
> seem to recall tcpdump showing me that DHCP packets were moving in the
> correct directions also.

Could you check tcpdump on your relay host as follow please:

#1
tcpdump -i br-lan host 10.75.22.247 and udp port 67

#2
tcpdump -i br-guest host 10.75.22.247 and udp port 67

with #1 you should only see message between your relay host and server