Internet & modems

'Cannot obtain IP address' error

This message means your device or router failed to get network configuration automatically, usually pointing to a DHCP problem on the router, a modem needing a restart, or in rare cases an ISP-side provisioning issue.

Difficulty
Moderate
Time
15–30 minutes
DIY cost
$0
Pro cost
$0–$100

Symptoms

  • Device shows 'unable to obtain IP address' or similar
  • Wi-Fi or Ethernet shows connected but no actual network access
  • Router's own WAN connection status shows no IP address assigned
  • Problem started after a modem or router restart, or after an outage

Likely causes

  • CommonRouter's DHCP client failing to get an address from the modem/ISPIf the router itself can't get a WAN IP address from the provider, none of your devices behind it will have real internet access even if local Wi-Fi seems fine.
  • CommonModem needs a restart to release its previous IP assignmentModems sometimes hold onto an IP lease that needs to be cleared with a restart before a new one can be issued.
  • PossibleMAC address of the router changed and the ISP's system needs to recognize the new deviceSome providers tie the internet connection to the specific MAC address of the first router or computer used, especially after swapping equipment.
  • PossibleLocal device-level network configuration issueIf only one device shows this error while others work, the issue is local to that device rather than the network as a whole.

What to do

  1. Restart the modem first, waiting for it to fully reconnect, then restart the router.
  2. Check the router's WAN/internet status page to see if it shows an IP address; if it shows 0.0.0.0 or blank, the router itself isn't getting an address from the ISP.
  3. If you recently changed routers, some ISPs require 'MAC cloning' (matching the new router's address to the old one) or a call to the provider to register the new device.
  4. On an individual device with the error, try 'forget network and reconnect' for Wi-Fi, or run ipconfig /release then /renew on Windows.
  5. Try connecting a single computer directly to the modem via Ethernet (bypassing your router temporarily) to see if it gets an IP address, which helps isolate whether the modem or router is at fault.
  6. Check for a firmware update on the router, since DHCP client bugs are occasionally fixed in updates.
  7. If the router still can't obtain a WAN IP address after these steps, contact your ISP, since they may need to reset your line's provisioning or check for an account issue.

Tools and parts

  • Ethernet cable for isolating modem vs router

When to call a pro

If the router can't get a WAN IP address even connected directly to a freshly restarted modem, your ISP needs to check or reset the account's provisioning on their end.

Safety

Generally low risk

Generally low risk for a careful person. Stop if anything looks different from what this guide describes.

Related guides

Operator provides AI-generated troubleshooting information. It can be wrong. For safety-critical, electrical, gas, structural, medical, automotive safety, or other high-risk problems, consult a qualified professional.