UPDATE: This has been fixed for a while now, but it took me a lot longer to track down than I care to admit. The problem? The kit from my ISP used the default network of 192.168.0.0/24, and OpenWRT uses 192.168.1.0/24 by default. And I hadn't updated my ufw configuration. As soon as I did that, presto! A working LAN. sigh
1294 0 jj@ALICE:~$ nmap -Pn -A -p- --reason -vvvvvv BOB Starting Nmap 7.80 ( https://nmap.org ) at 2020-09-19 14:12 BST NSE: Loaded 151 scripts for scanning. NSE: Script Pre-scanning. NSE: Starting runlevel 1 (of 3) scan. Initiating NSE at 14:12 Completed NSE at 14:12, 0.00s elapsed NSE: Starting runlevel 2 (of 3) scan. Initiating NSE at 14:12 Completed NSE at 14:12, 0.00s elapsed NSE: Starting runlevel 3 (of 3) scan. Initiating NSE at 14:12 Completed NSE at 14:12, 0.00s elapsed Initiating Parallel DNS resolution of 1 host. at 14:12 Completed Parallel DNS resolution of 1 host. at 14:12, 0.03s elapsed DNS resolution of 1 IPs took 0.04s. Mode: Async [#: 1, OK: 1, NX: 0, DR: 0, SF: 0, TR: 1, CN: 0] Initiating Connect Scan at 14:12 Scanning eee.lan (BOB) [65535 ports] Connect Scan Timing: About 0.31% done Connect Scan Timing: About 0.53% done Connect Scan Timing: About 0.76% done Connect Scan Timing: About 0.98% done Connect Scan Timing: About 1.21% done; ETC: 17:51 (3:37:09 remaining) Connect Scan Timing: About 5.88% done; ETC: 17:51 (3:26:08 remaining) Connect Scan Timing: About 10.84% done; ETC: 17:50 (3:15:11 remaining) Connect Scan Timing: About 15.85% done; ETC: 17:50 (3:04:11 remaining) Connect Scan Timing: About 20.86% done; ETC: 17:50 (2:53:12 remaining) Connect Scan Timing: About 25.86% done; ETC: 17:50 (2:42:14 remaining) Connect Scan Timing: About 30.87% done; ETC: 17:50 (2:31:17 remaining) Connect Scan Timing: About 35.88% done; ETC: 17:50 (2:20:18 remaining) Connect Scan Timing: About 40.89% done; ETC: 17:50 (2:09:21 remaining) Connect Scan Timing: About 45.89% done; ETC: 17:50 (1:58:24 remaining) Connect Scan Timing: About 50.90% done; ETC: 17:50 (1:47:26 remaining) Connect Scan Timing: About 55.92% done; ETC: 17:50 (1:36:27 remaining) Connect Scan Timing: About 60.94% done; ETC: 17:50 (1:25:29 remaining) Connect Scan Timing: About 65.95% done; ETC: 17:50 (1:14:31 remaining) Connect Scan Timing: About 70.96% done; ETC: 17:50 (1:03:33 remaining) Connect Scan Timing: About 75.97% done; ETC: 17:50 (0:52:35 remaining) Connect Scan Timing: About 80.97% done; ETC: 17:50 (0:41:38 remaining) Connect Scan Timing: About 85.98% done; ETC: 17:50 (0:30:41 remaining) Connect Scan Timing: About 90.98% done; ETC: 17:50 (0:19:44 remaining) Connect Scan Timing: About 95.99% done; ETC: 17:50 (0:08:47 remaining) Completed Connect Scan at 17:50, 13130.84s elapsed (65535 total ports) Initiating Service scan at 17:50 NSE: Script scanning BOB. NSE: Starting runlevel 1 (of 3) scan. Initiating NSE at 17:50 Completed NSE at 17:50, 0.00s elapsed NSE: Starting runlevel 2 (of 3) scan. Initiating NSE at 17:50 Completed NSE at 17:50, 0.00s elapsed NSE: Starting runlevel 3 (of 3) scan. Initiating NSE at 17:50 Completed NSE at 17:50, 0.00s elapsed Nmap scan report for eee.lan (BOB) Host is up, received user-set. All 65535 scanned ports on eee.lan (BOB) are filtered because of 65535 no-responses NSE: Script Post-scanning. NSE: Starting runlevel 1 (of 3) scan. Initiating NSE at 17:50 Completed NSE at 17:50, 0.00s elapsed NSE: Starting runlevel 2 (of 3) scan. Initiating NSE at 17:50 Completed NSE at 17:50, 0.00s elapsed NSE: Starting runlevel 3 (of 3) scan. Initiating NSE at 17:50 Completed NSE at 17:50, 0.00s elapsed Read data files from: /usr/bin/../share/nmap Service detection performed. Please report any incorrect results at https://nmap.org/submit/ . Nmap done: 1 IP address (1 host up) scanned in 13131.71 seconds