PCI Passthrough of NIC to FreeBSD environment does not receive unicast traffic

This passthrough worked in XenServer 6.5 (identical VM definitions)

VM Properties:
other-config (MRW): vgpu_pci: ; pci: 0/0000:07:00.0,1/0000:07:00.1; base_template_name: Other install media; mac_seed: 2fbc83e7-ef53-c5f9-7bd4-63647ba6cea3; install-methods: cdrom
VCPUs-number ( RO): 2
VCPUs-utilisation (MRO): 0: 0.016; 1: 0.001
os-version (MRO): name: FreeBSD 10.3-RELEASE-p3; uname: 10.3-RELEASE-p3; distro: FreeBSD
PV-drivers-version (MRO): major: 6; minor: 2; micro: 0; build: 76888
PV-drivers-up-to-date ( RO): true
networks (MRO): 1/ip: 10.1.5.3; 0/ip: 10.1.0.210
PV-drivers-detected ( RO): true

When the VM is booted using some linux install media (archlinux-2016.05.01-dual.iso, ClearOS-DVD-x86_64.iso) I experience no issues talking with the NIC. I get a DHCP address and ARP entries are formed without problem. I'm able to talk out to any resource I choose using any protocol.

If, however, I boot this VM using the FreeBSD install media (FreeBSD-10.3-RELEASE-amd64-dvd1.iso, OPNsense-16.1.8-OpenSSL-cdrom-amd64.iso, pfSense-CE-2.3.1-RELEASE-amd64.iso) and complete the installation, unicast traffic is not visible. I am able to get a DHCP address if a port is connected to my existing network, however this is where it all stops. I can see broadcast traffic on the interface (both IPv4 and IPv6) via tcpdump, however I cannot form any neighbour associations or receive any ARP responses. The router on the existing network observes the arp who-has requests and when appropriate sends a response. The response, however, does not show up on on either port or in the firewall log of the VM.