THE SHORT ANSWER

If the modem has internet but the router says no internet, restart in the right order: modem first, wait until it is fully online, then router. Confirm the modem-to-router cable is in the router WAN/internet port, then check whether the router received a WAN IP address.

Do not reset the whole router first. Most of these cases are handoff problems between two boxes, not a destroyed Wi-Fi setup.

The modem and router can disagree because they do different jobs

A modem can be online while the router still has no usable internet. That sounds contradictory, but the two devices are responsible for different parts of the connection. The modem talks to the provider line. The router takes that connection, creates your home network, gives devices addresses, handles Wi-Fi and sends traffic out through the modem. If the modem is ready but the router misses the handoff, your devices can join Wi-Fi and still go nowhere.

This often happens after an outage, a new router, a power cut, a cable swap, bridge mode change or a modem restart. The fix is usually calm and boring: check the physical link, restart in sequence and look at the router WAN status before changing every setting.

Quick diagnosis table

What you seeLikely causeTry first
Modem online, router red or amberWAN handoff failedRestart modem first, then router
Router WAN IP is blankNo lease from modem/providerCheck WAN cable and boot order
Direct modem test worksRouter setup problemCheck router internet settings
Direct modem test fails tooProvider/modem issueCall provider with modem status

Try these fixes in order

Work from the modem outward. The goal is to prove whether the internet stops at the modem, the cable between boxes, or the router WAN settings.

  1. 01

    Restart in modem-first order

    Unplug modem and router. Start the modem first and wait until the online light is stable. Then power the router and wait for its internet light.

  2. 02

    Check the WAN port

    The cable from the modem should go into the router port marked WAN, internet or a globe symbol. A LAN port can make the router look alive but offline.

  3. 03

    Swap the Ethernet cable

    A weak cable between modem and router can create a no-internet state even when both devices have power and lights.

  4. 04

    Check WAN IP status

    In the router app or admin page, look for WAN IP, internet IP or connection status. Blank, 0.0.0.0 or no IP is the key clue.

  5. 05

    Disconnect extra network gear

    Remove switches, mesh nodes or old routers for one test. Modem to router only gives the cleanest result.

  6. 06

    Return router internet settings to automatic

    Most home connections use automatic/DHCP on the router WAN side. Static IP, PPPoE or custom DNS can break the handoff if copied from another setup.

  7. 07

    Call the provider if the modem will not pass an IP

    If the router still receives no WAN address after cable and restart checks, the provider may need to clear provisioning, modem mode or account state.

Detailed checks

CHECK 01

Boot order matters more than people think

The router asks the modem for a usable internet address. If the router starts before the modem has finished reconnecting, it may ask too early and sit there offline.

  • That is why modem-first restart advice appears in so many router forums.
  • Give the modem several quiet minutes before powering the router.
CHECK 02

The WAN IP is the honest clue

Router lights can be vague, but WAN status is direct. If the WAN IP is missing, the router has not received a usable address from the modem side.

  • If the WAN IP exists but websites fail, the issue may be DNS or routing.
  • Those two cases should not be fixed the same way.
CHECK 03

Bridge mode changes the story

Some provider gateways act as modem and router together. If bridge mode is enabled, only one device behind it may receive the public connection.

  • If you moved cables or added a new router, bridge mode can make the old setup stop making sense.
  • Check provider gateway mode before blaming Wi-Fi.
CHECK 04

Direct modem tests are useful but awkward

A direct wired test can prove whether the modem itself passes internet, but many providers bind the connection to one device until rebooted.

  • If you test a laptop directly, restart the modem before reconnecting the router.
  • Otherwise the router may still fail because the modem is holding the old lease.
CHECK 05

New routers fail here often

A new router can broadcast Wi-Fi immediately, which makes the setup feel almost done. But internet still depends on the WAN side.

  • Wrong port, early boot, copied static settings or provider device registration can all leave it offline.
  • Finish the WAN test before customizing Wi-Fi names.
CHECK 06

What to say to support

Tell support the modem online light is stable, the router says no internet and the router WAN IP is blank or missing.

  • That sentence is much better than saying the Wi-Fi is broken.
  • It points them to provisioning, bridge mode and modem handoff.

Mistakes to avoid

Do not plug the modem cable into a normal LAN port.

Do not restart only the router if the modem just came back from an outage.

Do not assume full Wi-Fi bars mean the router has internet.

FAQ

Why does my modem have internet but my router says no internet?

The modem may be connected to the provider while the router has not received a usable WAN IP address. That can happen because of boot order, a bad Ethernet cable, wrong port, bridge mode or provider lease behavior.

Check the router internet status page. If WAN IP is blank or 0.0.0.0, focus on the handoff between modem and router before touching device settings.

Should I restart the modem or router first?

Restart the modem first. Wait until the online light is stable, then start the router. This lets the router ask for internet after the modem is ready.

Starting both at the same time sometimes works, but modem-first is cleaner when the router keeps saying no internet.

Can a bad Ethernet cable cause this?

Yes. The cable between modem and router carries the internet handoff. If it is damaged, loose or plugged into the wrong port, the router can broadcast Wi-Fi without internet.

Swap the cable for one known-good cable. It is one of the fastest tests and does not change settings.

What does WAN IP blank mean?

It means the router has not received the address it needs on the internet side. In plain English, the router is awake but has not been handed a route out of the house.

If it stays blank after a modem-first restart and cable swap, contact the provider or check bridge/provisioning settings.

Should I clone the MAC address?

Only use MAC cloning if your provider or router manual specifically points to it. Some connections remember the device that was previously connected to the modem, but many modern setups do not need cloning.

A modem reboot after reconnecting the router is usually the safer first move.

Why does direct modem internet work but router internet does not?

That usually means the provider line is alive and the router side needs attention. Check WAN port, WAN IP, automatic internet settings, firmware and any bridge mode or passthrough settings.

After direct modem testing, restart the modem again before plugging the router back in so the lease can refresh.

When should I call my internet provider?

Call when the modem is online but no router receives a WAN IP after a proper restart, cable swap and simple direct test.

Ask them to check whether the modem is provisioned correctly, whether bridge mode is active and whether the modem is passing an address to your router.

RELATED TROUBLESHOOTINGUse these next if the symptom changes.New router setup →Router lights →Provider example →
HELPFUL REFERENCES

Outside references