Problems installing on a Netgear WNDR 4300v1

I have two routers: a Netgear WNDR 3700v2 and a WNDR 4300v1. I recently installed LEDE 17.01.0 on both of them. Everything works fine on the 3700 including the LAN, the WLAN and the WAN.

But on the 4300 only the LAN and WLAN work. I cannot even ping the Cisco DPC3008 DOCSIS 3.0 cable modem. I've swapped these routers in and out several times with the same results. And I've done a complete reinstall of 17.01.0, again with the same results. Also, I know that I need to power down and disconnect both my cable modem and router when I'm performing a swap like this.

Here are the LAN and WAN configurations for the two routers:

ifconfig for the 4300:

eth0.1 Link encap:Ethernet HWaddr 04:A1:ZZ:80:ZZ:31
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:1170 errors:0 dropped:0 overruns:0 frame:0
TX packets:903 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:137756 (134.5 KiB) TX bytes:152567 (148.9 KiB)

eth0.2 Link encap:Ethernet HWaddr 04:A1:ZZ:80:ZZ:32
inet6 addr: fe80::6a1:51ff:fe80:ea32/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:177 errors:0 dropped:0 overruns:0 frame:0
TX packets:47 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:25472 (24.8 KiB) TX bytes:12818 (12.5 KiB)

ifconfig for the 3700:

eth0 Link encap:Ethernet HWaddr C6:3D:ZZ:B0:ZZ:0E
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:63577 errors:0 dropped:0 overruns:0 frame:0
TX packets:74785 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:10723147 (10.2 MiB) TX bytes:35311551 (33.6 MiB)
Interrupt:4

eth1 Link encap:Ethernet HWaddr C4:3D:ZZ:B0:ZZ:0F
inet addr:24.17.227.49 Bcast:24.17.231.255 Mask:255.255.248.0
inet6 addr: 2001:558:600a:61:2531:e9a8:c4b0:402a/128 Scope:Global
inet6 addr: fe80::c63d:c7ff:feb0:280f/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:760515 errors:0 dropped:0 overruns:0 frame:0
TX packets:310367 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:916977504 (874.4 MiB) TX bytes:39075544 (37.2 MiB)
Interrupt:5