Network troubleshooting technician providing live chat help

Joe B.

Expert ★★★★★ 27,853 satisfied customers

Specialities: Home networking, cable/DSL modems, WAN IP/DHCP issues, Wi-Fi routers, ISP provisioning & MAC binding

Fix “modem not obtaining IP” — WAN IP 0.0.0.0, router not getting IP from ISP, DHCP lease failures

Technician avatar Technician
Hi! We’ll figure out why your modem is not obtaining an IP address and get your internet back. I just need a quick picture of how everything is connected.

• What kind of modem/router setup do you have — separate modem + Wi-Fi router, or a single gateway from your ISP?
• On the router/modem status page, what does the Internet / WAN IP show — a normal address, 0.0.0.0, or “Not available”?
• On a computer plugged in by Ethernet, does Windows/macOS say “No valid IP configuration” or show a 169.254.x.x self-assigned IP?
• Finally, have you recently changed anything — new router, new ISP, or moved cables around?

Once we know whether the modem is not getting an IP from the ISP or the router is not obtaining IP from the modem, we’ll walk through the exact DHCP and WAN settings to fix it.
Customer
We have a separate Arris cable modem and a Netgear Wi-Fi router. Since yesterday the internet has been down. In the Netgear web interface the Internet IP address is 0.0.0.0 and it says “Disconnected”. If I plug my Windows PC straight into the modem, it says “Ethernet doesn’t have a valid IP configuration” and gets a 169.254 address. I’ve rebooted both devices multiple times but the modem still isn’t obtaining an IP.
Technician avatar Technician
Thanks, that’s really clear and it fits the pattern.

When a modem doesn’t obtain an IP address from the ISP and any device behind it sees 0.0.0.0 or 169.254.x.x, it usually means the DHCP “handshake” on the WAN side isn’t completing. Typical causes are:

• The ISP’s DHCP server is not assigning an IP (outage, maintenance, or bad profile).
• The modem is still locked to another MAC address and won’t give a lease to your current router or PC.
• Wrong connection type (using DHCP when your ISP requires PPPoE, static IP, or special VLAN settings).
• A provisioning issue after a new modem or new account is activated.

We’ll first do a “clean” reboot in the right order so the modem can request a fresh IP from the ISP, then we’ll check whether your modem is not obtaining IP at all or if it’s the router WAN not getting IP from the modem.
Customer
The ISP did recently bump our speed and I had to restart everything once, but it was working after that. Now the Internet IP = 0.0.0.0 on the router and Windows shows that self-assigned 169 address if I go directly into the modem. The modem’s lights look normal though — power, downstream, upstream, and online are all solid.
Technician avatar Technician
Good detail. Many cable providers “remember” the first device they see and won’t hand out a new IP address until the modem is fully reset and sees that device again.

Step A — Clean power cycle to clear stale DHCP lease
1) Power off your router and modem (unplug both from the wall).
2) Connect your PC directly to the modem with an Ethernet cable. Leave the router unplugged for now.
3) Wait at least 60–90 seconds, then plug the modem back in and let it fully boot until the online light is solid.
4) On Windows, open Command Prompt and run:
  • ipconfig /release
  • ipconfig /renew
5) Run ipconfig again and check if the PC now has a normal public/private IP and a valid default gateway from the ISP, instead of 169.254.x.x.

If your PC still can’t get an IP from the modem and the modem is not obtaining IP from the ISP, that points to either a provisioning issue or a DHCP problem on the ISP side. If the PC works but the router still shows WAN IP 0.0.0.0 later, then the router-modem relationship is what we’ll tune.
Customer
I followed those steps. With just the PC plugged into the modem, after rebooting and doing ipconfig /renew, it actually did get a real IP and I could browse the web. So directly connected, the modem does obtain an IP from the ISP. But the moment I put the Netgear router back in, the router’s Internet IP goes back to 0.0.0.0 and all devices lose internet again.
Technician avatar Technician
Perfect test — that tells us the modem is getting an IP fine, but the router WAN is not obtaining IP from the modem.

ISPs that “lock” to a MAC will only hand out an address to the device they saw last — in your case, your PC. When you swap the router back in, the modem still thinks the PC should get the lease.

Step B — Make the router look like the working PC
• Log in to the Netgear router’s web interface and go to Internet / WAN setup.
• Confirm the connection type is set to “Get dynamically from ISP (DHCP)” unless your ISP specifically requires PPPoE or static IP.
• Use the router’s “MAC address clone” feature and clone the MAC address from the PC that successfully got an IP from the modem.
• Save/apply those settings.
• Now power off the modem and router again. Turn the modem on first, wait until online is solid, then turn on the router.

After 1–2 minutes, check the router’s status page again. If everything is correct, the Internet / WAN IP should now show a real address, not 0.0.0.0, and your devices should come back online.
Customer
I set Internet to “get dynamically from ISP” and cloned the PC’s MAC address onto the router, then powered everything down and back up in that order. Now the Netgear shows an actual WAN IP address instead of 0.0.0.0 and the status says “Connected”. However, my Windows laptop was still saying “No internet” until I ran the network troubleshooter and did another ipconfig /renew.
Technician avatar Technician
Great — that means we’ve solved the main modem/router not obtaining IP issue and now we’re just cleaning up device settings.

When the WAN side was broken, some devices cached bad info or self-assigned an address. To fix that:

Step C — Refresh local IP & DNS on devices
1) On each computer or phone, make sure the network adapter is set to obtain IP address automatically (DHCP) and DNS server automatically (unless you intentionally use custom DNS).
2) Forget and reconnect to the Wi-Fi network or unplug/replug Ethernet so the device requests a new lease now that the router has a valid WAN IP.
3) On Windows you can run:
  • ipconfig /release
  • ipconfig /renew
  • ipconfig /flushdns
4) Test websites on two or three devices to confirm they get a proper local IP (192.168.x.x), a default gateway, and working DNS.

If every device now works, the modem not obtaining IP / WAN IP 0.0.0.0 problem is fully resolved. If one or two stubborn devices still misbehave, we’ll reset their network settings individually.
Customer
After renewing IP and DNS, my laptop and phone both work normally now. The router’s WAN IP looks good and stays connected. The only thing I noticed is that after a long power outage, the router once again showed 0.0.0.0 on the Internet IP until I rebooted the modem. Is that the same “modem not obtaining IP” problem coming back?
Technician avatar Technician
That’s related but slightly different. After power loss, sometimes the router boots faster than the modem. The router sends its DHCP request before the modem is fully online, so the WAN IP falls back to 0.0.0.0 and looks like the modem is not obtaining IP when really the timing is just off.

To reduce that:
• Always let the modem boot completely first (all status LEDs solid) before powering the router.
• If your router has a “Check Internet connection” or auto-renew feature, enable it so it automatically retries DHCP when WAN is 0.0.0.0.
• Keep the MAC clone enabled so the ISP always sees a familiar device when handing out the IP address.

If the WAN IP keeps dropping to 0.0.0.0 frequently even when everything powers on cleanly, then we’d look deeper at ISP DHCP lease times, firmware updates, or a flaky modem.
Customer
Understood. I changed our habit so we power up the modem first and give it a few minutes before turning on the router. Since doing that, the router hasn’t gone back to 0.0.0.0 and the modem always seems to obtain an IP without problems.
Technician avatar Technician
Perfect — that’s usually all it takes to turn a flaky setup into a stable one.

Step D — Make sure the “not obtaining IP” issue doesn’t return
• Turn on automatic firmware updates for both modem (if supported) and router, or check for updates every month or two.
• Keep the router’s Internet connection type on the setting your ISP expects (usually DHCP, sometimes PPPoE or static IP) and avoid random changes under WAN unless you know why.
• Leave the MAC address clone set to the working PC’s MAC if your ISP is picky about devices.
• If you ever replace the modem or router, be ready to repeat a quick power-cycle + clone MAC sequence if you see WAN IP 0.0.0.0 or the modem not obtaining an IP from the ISP.

With those in place, you shouldn’t have to think about DHCP leases or WAN addresses again — your modem and router should quietly obtain IP addresses and stay online in the background.
Customer
That all makes sense now. I didn’t realize that a modem not obtaining an IP or a router showing 0.0.0.0 was mostly a DHCP and MAC issue. I’ve saved the steps so if it happens again I know what to do.
Technician avatar Technician
You got it.

Summary: To fix modem not obtaining IP or WAN IP 0.0.0.0, first test a PC directly on the modem, then:
• Power cycle modem and router in the correct order.
• Use the proper Internet connection type (DHCP vs PPPoE vs static).
• Clone the working device’s MAC address if your ISP locks to a MAC.
• Refresh IP/DNS on your devices after the router gets a valid WAN IP.

If you ever get stuck again — WAN IP 0.0.0.0, “unable to obtain IP address from ISP”, or “Ethernet doesn’t have a valid IP configuration” — you can open a chat with an expert and we’ll trace it live with you.
Customer
Awesome, thanks. Everything’s back up and now I actually understand what “modem not obtaining IP” and “WAN IP 0.0.0.0” really mean. Really appreciate the step-by-step help!
Technician avatar Technician
Any time! If a friend or coworker complains that their modem is not obtaining an IP address, their router’s WAN IP is 0.0.0.0, or their devices show “no valid IP configuration”, you can share this checklist — and if you’d like someone to click through the modem and router settings with you in real time, just start a chat with an expert and we’ll take it from there.

Quick answer: the accepted fix

Accepted fix when a modem is not obtaining IP and the WAN IP shows 0.0.0.0: test a PC directly on the modem, then power cycle the modem and router in order, set the correct Internet connection type (DHCP, PPPoE, or static), and use MAC address cloning if your ISP locks service to a specific device. Once the router gets a valid WAN IP, refresh device IP/DNS so “no valid IP configuration” clears on all computers and phones.

Why modems and routers fail to obtain an IP address (WAN IP 0.0.0.0, DHCP, MAC binding)

Most “modem not obtaining IP” issues come down to how your modem, router, and ISP’s DHCP server talk to each other. If the ISP doesn’t offer a lease or offers it only to a specific MAC address, your modem or router ends up with WAN IP 0.0.0.0 or your PC gets a 169.254.x.x self-assigned IP. Changing hardware, resetting devices in the wrong order, or switching ISPs without updating WAN settings all increase the chances of this happening.

Breaking the path into pieces — device → router → modem → ISP DHCP — makes diagnosis much easier. If a PC directly connected to the modem gets a valid IP, the modem is obtaining an IP from the ISP and the problem is only that the router WAN is not obtaining IP from the modem. If nothing gets a proper address and every device falls back to 169.254.x.x, the modem itself is not getting a lease and the ISP side needs attention.

How to check whether “not obtaining IP” is modem, router, or ISP

To quickly narrow down a modem not obtaining IP problem, start simple and test one link at a time.

First, connect a computer directly to the modem and reboot the modem. If the PC receives a proper IP address and you can browse, the ISP and modem DHCP are working. When you reconnect your router, check its Internet / WAN status: if the WAN IP is 0.0.0.0 or “Not available”, the router is not obtaining an IP address from the modem. That’s when cloning MAC, correcting WAN type, and doing a clean power cycle are most effective. If the PC never gets an IP address directly from the modem, the modem is not being assigned an IP by the ISP and you’ll likely need your provider to reprovision or reset your line.

Modem not obtaining IP — quick troubleshooting tips

Confirm the modem’s WAN IP and DHCP lease before chasing Wi-Fi problems.

Fast path: bypass the router and test a PC directly → power cycle modem for 60–90 seconds → verify the PC gets a valid IP from the ISP → reconnect the router, set the proper Internet connection type, and clone the working device’s MAC if needed → reboot in the order modem first, router second until the router’s WAN IP is no longer 0.0.0.0. Then refresh IP/DNS on each device. This solves the majority of “modem not obtaining IP address” and “WAN IP 0.0.0.0” situations at home.

Disclaimer: This information is AI-generated and intended for general guidance only. For advice specific to your modem model and ISP, please consult a verified expert on Whizz-Tech before making decisions.

Getting Started Is Easy

Ask for help, 24/7

Members enjoy round-the-clock access to 12,000+ verified Experts for modem not obtaining IP, WAN IP 0.0.0.0, no valid IP configuration, and more.

Expert will respond in minutes

We match you with a networking specialist who understands modems, DHCP leases, MAC binding, and router WAN setup for all major ISPs and brands.

Save time & money

Skip the endless reboots and long ISP calls. Get a clear step-by-step fix for modem not obtaining IP and WAN IP 0.0.0.0 issues directly in chat.

FAQ

Why is my modem not obtaining an IP address?

A modem not obtaining an IP address usually means the ISP’s DHCP server isn’t completing the lease process. Common causes are a modem that’s still locked to a previous device’s MAC address, wrong connection type (DHCP vs PPPoE vs static IP), an unprovisioned or newly replaced modem, or a temporary ISP outage. Testing a PC directly on the modem and checking if the WAN IP is 0.0.0.0 helps show whether the problem is your router or the ISP side.

What does WAN IP 0.0.0.0 mean on my router?

If your router’s Internet / WAN IP shows 0.0.0.0, it usually means the router did not obtain an IP address from the modem or ISP. The modem may still be booting, may be bound to another MAC address, or the WAN settings (DHCP/PPPoE/static) may be wrong. Power cycling the modem and router in the right order, cloning the MAC address of a device that works directly with the modem, and verifying the correct connection type are the standard fixes.

How do I fix “Ethernet doesn’t have a valid IP configuration”?

This Windows error appears when your PC cannot obtain an IP address from the network. If you see it while plugged into the router, check whether the router has a valid WAN IP and that DHCP is enabled on the LAN side. If you see it while plugged directly into the modem, the modem may not be obtaining an IP from the ISP. After confirming the modem and router are online, run ipconfig /release and ipconfig /renew and ensure the adapter is set to obtain IP and DNS automatically.

When should I call my ISP about IP address problems?

Call your ISP if a PC connected directly to the modem cannot obtain an IP, the modem’s WAN IP stays at 0.0.0.0, or your devices only get 169.254.x.x self-assigned addresses even after a full power cycle. Tell them your modem is not obtaining an IP address and provide any error messages from the modem or router status page. If they confirm the line looks good but your hardware still can’t get an IP, it may be time to replace the modem or have the ISP reprovision it.

Sources

Matt Verified Icon
Matt ● replies in < 1 min
Technician Expert
⭐⭐⭐⭐⭐ Trusted by 27,000+ customers
Avatar
Alex · Expert's Assistant
5 Tech Support Specialists are online right now.