I have a Keenetic Extra DSL router. I configured a static DHCP reservation so that my ESP32-W5500 device (MAC: de:ad:be:ef:fe:01) always receives 192.168.1.114. There's a MAC-based port forwarding rule for port 80, and a defined [subdomain].keenetic.pro points to this device as well.

After a soft-restart, port forwarding silently breaks for WAN traffic. The rule appears active in the panel, but incoming connections from the outside just time out.

This has recurred consistently across multiple soft-reload events over several months, with a different "ghost" IP each time (.100, .101, .102).

From the local network, however, I can always reach the client on its assigned static IP (.114) without any interruption. And here's the kicker: if I simply disable and re-enable the port forwarding rule from the router's interface, the problem vanishes instantly and external WAN access comes right back.

The weird part: during an outage, when I look at the router's own diagnostic tools, the ARP table and the NAT table completely contradict each other.

From the router's system logs:

DHCP is working correctly

16:34:35 — Client requests .101 16:34:35 — Router sends NAK, rejects it 16:34:35 — Client sends DISCOVER; router offers the reserved .114 16:34:35 — Client receives ACK for .114

Nginx proxy connects to the wrong IP 4 seconds after DHCP

16:34:39 — activated proxy [subdomain].keenetic.pro to http://192.168.1.101:80

Nginx "corrects" itself within 2 seconds

16:34:41 — activated proxy [subdomain].keenetic.pro to http://192.168.1.114:80

But nginx correcting itself does not stop incoming traffic from still being forwarded to the .101 ghost IP, as the CLI logs below show.

19:00:59 — CLI capture:

show ip neighbour:

id: 6 via: de:ad:be:ef:fe:01 address: 192.168.1.101 expired: yes ← INVALID

id: 7 via: de:ad:be:ef:fe:01 address: 192.168.1.114 expired: no ← VALID

show running-config | grep "ip static":

ip static tcp PPPoE0 80 de:ad:be:ef:fe:01

show ip nat – incoming WAN port 80 traffic:

TCP 172.71.102.232 13498 [WANIP] 80 4 192.168.1.101 80 172.71.102.232 13498 4

TCP 172.71.102.232 10776 [WANIP] 80 4 192.168.1.101 80 172.71.102.232 10776 4

At 19:00:59, incoming traffic is still being forwarded to the .101 ghost IP.

Question for the experts: Is this a client-side issue, or does it point to a bug in the router?