FAQ
TL;DR: Fix "Wi‑Fi connected, no internet" on TP‑Link Archer C20 by using 2 DHCP menus—"DHCP Settings" and "DHCP Address Reservation"—and, as one expert notes, "configure the DHCP server." [Elektroda, KOCUREK1970, post #16933005]
Why it matters:** It solves roaming dropouts and wrong IPs on phones, laptops, and tablets without buying new hardware.
Who this is for: home users with radio/CPE internet feeding a TP‑Link Archer C20 who see Wi‑Fi but no internet.
Quick Facts
- Radio ISP path here: roof CPE → PoE/LAN power supply → TP‑Link router. [Elektroda, darq_1, post #16930471]
- Symptom pattern observed: 192.168.3.x = internet works; 192.168.2.x = no internet. [Elektroda, darq_1, post #16932127]
- Root cause explained: cable in LAN made TP‑Link act as AP; WAN lets TP‑Link’s DHCP assign IPs. [Elektroda, KOCUREK1970, post #16932975]
- Proven fix reported: move the ISP/CPE cable from LAN to WAN, then reconnect. [Elektroda, darq_1, post #16932951]
- To pin devices to stable IPs: use DHCP Settings → Address Reservation on Archer C20. [Elektroda, KOCUREK1970, post #16933005]
How do I fix “Wi‑Fi connected, no internet” on a TP‑Link Archer C20 with radio internet?
Plug the ISP/CPE cable into the router’s WAN port, not a LAN port. Reboot the router. Reconnect your devices to Wi‑Fi. This change lets the router issue correct IPs and restores internet access. Users confirmed the internet worked immediately after moving the cable. [Elektroda, darq_1, post #16932951]
Why do my devices get 192.168.2.x sometimes and 192.168.3.x other times?
They were receiving IPs from different DHCP sources. With the ISP cable in LAN, the TP‑Link behaved like an access point and didn’t assign addresses. With the cable in WAN, its DHCP server assigned the proper subnet. “When the cable is in the WAN, the DHCP server…assigns the IP.” [Elektroda, KOCUREK1970, post #16932975]
Where exactly should the PoE/CPE cable plug into the Archer C20?
Connect the Ethernet from the PoE/LAN power supply (feeding the roof CPE) to the blue WAN port on the Archer C20. After moving it from LAN to WAN, the reporter regained internet on all devices. [Elektroda, darq_1, post #16932951]
What is CPE in a radio internet setup?
CPE means Customer Premises Equipment. It’s the outdoor unit or antenna on your building that talks to the provider. Your router connects to the CPE via a PoE power supply and Ethernet. The helper clarified this when diagnosing the link path. [Elektroda, dt1, post #16931266]
What is a PoE/LAN power supply (injector)?
It’s the small adapter that powers the roof CPE through Ethernet and provides a LAN port for your router. In this case, the path was antenna → adapter → router. Ensure its LAN port feeds the router’s WAN port. [Elektroda, darq_1, post #16930471]
Is my Archer C20 acting as a router or just an access point?
If the ISP feed is in a LAN port, it behaves like an access point and typically doesn’t run DHCP. In the WAN port, it routes and assigns IPs via its DHCP server. That difference decides whether clients get working internet. [Elektroda, KOCUREK1970, post #16932975]
How do I reserve a static IP for a device on the Archer C20?
Open the TP‑Link UI. Go to DHCP → DHCP Settings to enable DHCP. Then use DHCP → DHCP Address Reservation to bind a device’s MAC to a chosen IP. Save and reboot clients for leases to refresh. “Configure the DHCP server” first. [Elektroda, KOCUREK1970, post #16933005]
My phone only works after forgetting the network—what’s happening?
The device kept a stale Wi‑Fi session while the router handed out a different subnet later. Forgetting and re‑joining renewed the lease and route. The user reported it recurred after leaving and returning home until the cabling/DHCP issue was fixed. [Elektroda, darq_1, post #16930284]
Do I need a second router for whole‑home Wi‑Fi here?
No. The thread confirms a single Archer C20 served the home. The issue was cabling and DHCP role, not the number of routers. Move the ISP cable to WAN and configure DHCP correctly. [Elektroda, darq_1, post #16932127]
How can I quickly verify the ISP feed without the router?
Connect the CPE/PoE LAN cable directly to a computer by Ethernet. Disable Wi‑Fi on that computer. Run ipconfig /all and check if you receive a valid address and gateway from the provider. Share those results if needed. [Elektroda, dt1, post #16932772]
Should I call my ISP for exact parameters?
Yes. One helper noted you could get the required settings in a “five‑minute phone call.” Ask about DHCP vs. PPPoE, VLANs, and any MAC binding. Then apply them on the Archer C20. [Elektroda, dt1, post #16933363]
Will a firmware update help stability on the Archer C20?
Updating to the latest TP‑Link firmware is recommended. After updating, re‑enter DHCP settings, set Address Reservations if needed, and export a config backup for safety. This improves reliability and recovery after changes. [Elektroda, KOCUREK1970, post #16933005]
What were the actual working vs. non‑working IP ranges in this case?
Working sessions used 192.168.3.x. Non‑working sessions showed 192.168.2.x. That mismatch flagged the DHCP role problem and guided the WAN‑port fix. The reporter observed this pattern before resolving the issue. [Elektroda, darq_1, post #16932127]
Three‑step how‑to: restore internet on Archer C20 with radio ISP
- Move the PoE/ISP Ethernet from a LAN port to the blue WAN port.
- Power‑cycle the Archer C20.
- Reconnect devices to Wi‑Fi and test browsing.
Users confirmed success immediately after step 1 in this case. [Elektroda, darq_1, post #16932951]
Edge case: Why didn’t toggling Wi‑Fi on my phone fix it permanently?
Toggling Wi‑Fi only refreshed the device session. It didn’t correct the router’s role. The connection failed again after leaving range, until the cable was moved to the WAN port and DHCP served consistent leases. [Elektroda, darq_1, post #16930284]
Quick check: how many routers were involved here?
Exactly one. The poster confirmed no second router existed. That ruled out double‑NAT and focused troubleshooting on the Archer C20’s port and DHCP configuration. [Elektroda, darq_1, post #16932127]