u/le_avion

I've been using the ASUS ZenWiFi XT9 mesh router with the pi-hole for a long while but suddenly my query log started filling up with a flood of requests that return a NXDOMAIN response which result in the FTL-queries getting expanded non-stop .

AAAA null 192.168.129.67 OK (cache) NXDOMAIN (0.0ms)
A null 192.168.129.67 OK (cache) NXDOMAIN (0.0ms)

[2026-05-18 01:41:00.637 6746M] Resizing "FTL-queries" from 12845056 to (245760 * 56) == 13762560 (/dev/shm: 14.9MB used, 2.1GB total, FTL uses 14.9MB)
[2026-05-18 01:43:56.100 6746M] Resizing "FTL-queries" from 13762560 to (262144 * 56) == 14680064 (/dev/shm: 15.8MB used, 2.1GB total, FTL uses 15.8MB)
[2026-05-18 01:46:53.037 6746M] Resizing "FTL-queries" from 14680064 to (278528 * 56) == 15597568 (/dev/shm: 16.8MB used, 2.1GB total, FTL uses 16.7MB)
[2026-05-18 01:50:00.138 6746/T6780] Notice: Database size is 8416.49 MB, deleted 2191 rows
[2026-05-18 01:50:02.427 6746M] Resizing "FTL-queries" from 15597568 to (294912 * 56) == 16515072 (/dev/shm: 17.7MB used, 2.1GB total, FTL uses 17.6MB)
[2026-05-18 01:53:32.350 6746M] Resizing "FTL-queries" from 16515072 to (311296 * 56) == 17432576 (/dev/shm: 18.6MB used, 2.1GB total, FTL uses 18.5MB)
[2026-05-18 01:56:45.228 6746M] Resizing "FTL-queries" from 17432576 to (327680 * 56) == 18350080 (/dev/shm: 19.5MB used, 2.1GB total, FTL uses 19.5MB)
[2026-05-18 02:00:00.264 6746/T6780] Notice: Database size is 8416.49 MB, deleted 2136 rows
[2026-05-18 02:00:08.590 6746M] Resizing "FTL-queries" from 18350080 to (344064 * 56) == 19267584 (/dev/shm: 20.4MB used, 2.1GB total, FTL uses 20.4MB)
[2026-05-18 02:03:11.866 6746M] Resizing "FTL-queries" from 19267584 to (360448 * 56) == 20185088 (/dev/shm: 21.3MB used, 2.1GB total, FTL uses 21.3MB)
[2026-05-18 02:06:14.924 6746M] Resizing "FTL-queries" from 20185088 to (376832 * 56) == 21102592 (/dev/shm: 22.3MB used, 2.1GB total, FTL uses 22.2MB)
[2026-05-18 02:09:12.961 6746M] Resizing "FTL-queries" from 21102592 to (393216 * 56) == 22020096 (/dev/shm: 23.2MB used, 2.1GB total, FTL uses 23.1MB)
[2026-05-18 02:10:00.191 6746/T6780] Notice: Database size is 8416.49 MB, deleted 2497 rows

Nothing has changed on my side. I am not sure what to do to stop this flood.

Pi-hole v5.18.3 FTL v5.25.2 Web Interface v5.21.