BeagleBone Black USB networking - DHCP failing to respond

For what it’s worth, from the BeagleBone trying to ping 192.168.7.1 does not show up in the “tcpdump -i usb0 -n” output. So there’s something goofy going on there. Likewise the usb0 entry in ifconfig shows that it has not really attempted much in the way of TX packets:

usb0 Link encap:Ethernet HWaddr B6:10:BA:3D:01:25
inet addr:192.168.7.2 Bcast:192.168.7.3 Mask:255.255.255.252
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:173 errors:0 dropped:0 overruns:0 frame:0
TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:53796 (52.5 KiB) TX bytes:2249 (2.1 KiB)

TX packets 8? I must’ve sent 30 pings over the wire to 192.168.7.1 (which my Mac does not have, it’s showing a 169.254 type of address despite multiple presses of the Renew DHCP Lease button in System Preferences.) The routing table clearly lists usb0 as the destination for 192.168.7.0/30 frames:
(from ip route ls)
192.168.7.0/30 dev usb0 proto kernel scope link src 192.168.7.2

Something’s definitely wrong here with the USB network driver. I don’t see any iptables rules in place. udhcpd is clearly receiving the DHCP requests and is clearly sending replies per its log, but nada over the wire.