"Unable to obtain IP address" error when connecting to Wi-Fi: What to do on Android and iPhone

You're trying to connect to your home or public Wi-Fi network, but your phone keeps showing a message "Failed to obtain IP address"** — and the internet remains unavailable. This problem is familiar to many: the device "sees" the network, tries to connect, but after a few seconds, an error appears. What's the cause and how to fix it?

This error means that your smartphone was unable to receive automatically IP address from the router via protocol DHCPWithout an IP address, a device cannot exchange data on the network—even if the password is entered correctly and the signal is stable. This could be due to issues with the phone's settings, the router's configuration, or even conflicts with other devices on the network.

In this article we will look at all working solutions to the problem, from simple (rebooting the router) to advanced (manually configuring IP and DNS). The instructions are suitable for Android (including Samsung, Xiaomi, Huawei) And iPhone (iOS). You'll also learn how to diagnose the problem and avoid it in the future.

1. Restarting your phone and router: why it works

Start with the simplest thing - rebooting devicesIn 30% of cases, the "Unable to obtain IP address" error disappears after a basic reset. Here's why:

• 🔄 Telephone: Temporary glitches in the Wi-Fi module or operating system may prevent IP address acquisition. Restarting clears the network settings cache.
• 📡 Router: A frozen DHCP server (which assigns IP addresses) or an overloaded device memory can cause errors. A power reset clears these conditions.

How to reboot correctly:

1. Turn off the router's power (pull the plug out of the socket or press the button Power).
2. Wait 30–60 seconds - this time is enough for the capacitors to discharge and the cache to clear.
3. Turn the router back on and wait until it boots up completely (the indicators should be steady).
4. Restart your phone (on Android: hold the power button → "Restart"; on iPhone: "Turn off" → turn on again).

After rebooting, try connecting to Wi-Fi again. If the error persists, proceed to the next step.

2. Checking DHCP settings on the router

If rebooting doesn't help, the problem may be in the settings. DHCP servers On the router. This server automatically assigns IP addresses to devices on the network. If it's disabled, malfunctioning, or has exhausted its address pool, the phone won't be able to connect.

How to check DHCP settings:

1. Connect to the router through another gadget (laptop, tablet) or via cable.
2. Open your router's control panel by entering into your browser 192.168.0.1 or 192.168.1.1 (the address is indicated on the device sticker).
3. Log in (default logins: admin/admin or admin/password).
4. Go to the section LAN or DHCP (the name depends on the router model).

Parameters to check:

⚠️ Attention: If there are many devices connected to the network (more than 50), and the IP address pool is small (for example, 192.168.1.100–150), your router may run out of addresses. Increase the range or disable unnecessary devices.

After making changes, save the settings (Save or Apply) and reboot the router. Try connecting to Wi-Fi again.

3. Manually assigning an IP address on the phone

If the router does not issue an IP automatically, you can assign one manuallyThis is a temporary solution, but it will help you check if the problem is related to DHCP.

Instructions for Android:

1. Open Settings → Wi-Fi.
2. Click on your network name and select Change network (or Additionally).
3. In the section IP settings select Static (or Manually).
4. Fill in the fields:
   • IP address: 192.168.1.X (Where X — a number from 10 to 99, not used by other devices).
   • Gateway: 192.168.1.1 (router address).
   • Network prefix length: 24.
   • DNS 1: 8.8.8.8 (Google DNS) or 1.1.1.1 (Cloudflare).

Save the settings and connect to the network.

Instructions for iPhone (iOS):

1. Go to Settings → Wi-Fi and tap the "i" icon next to your network.
2. In the section Configuring IPv4 select Manually.
3. Enter the same parameters as for Android (see above).
4. Save and try to connect.

⚠️ Attention: If the internet works after manual setup, the problem is definitely with the router's DHCP server. Reset your phone's settings to default. Automatic (DHCP) and configure the router (see section 2).

Make sure the selected IP is not in use by another device|Check the gateway address (it must match the router IP)|Use reliable DNS (8.8.8.8 or 1.1.1.1)|Don't forget to return the settings to DHCP after the test-->

4. Reset network settings on your phone

If the previous methods didn't work, try reset network settings on your phone. This will delete all saved Wi-Fi networks and passwords, and reset your mobile data and Bluetooth settings. The data on your phone (photos, applications) will not be affected..

For Android:

1. Open Settings → System → Reset settings (on some phones: Settings → General settings → Reset).
2. Select Reset Wi-Fi, mobile network, and Bluetooth settings.
3. Confirm the action.

For iPhone:

1. Go to Settings → General → Transfer or reset iPhone.
2. Select Reset → Reset network settings.
3. Enter your password and confirm.

After the reset, your phone will reboot. Try connecting to Wi-Fi again. If the error persists, proceed to the next section.

5. Checking MAC address conflicts and filtering

Some routers use MAC address filtering — unique identifiers of network devices. If your phone isn't whitelisted or its MAC address is blocked, the router won't assign it an IP address.

How to check MAC filtering:

1. Open your router's control panel (see section 2).
2. Find the section MAC Filter, Security or Access control.
3. Check if filtering is enabled. If so, check if your phone's MAC address is listed.

How to find out your phone's MAC address:

• Android: Settings → About phone → General information → Wi-Fi MAC address.
• iPhone: Settings → General → About → Wi-Fi Address.

If filtering is enabled, add your phone's MAC address to the list of allowed devices or disable filtering completely (if it is safe for your network).

Also check if there is MAC address conflict — when two devices on the network have the same MAC address (rare, but can happen after address cloning). In this case, the router may become confused and not assign an IP address.

6. Updating the router and phone firmware

Outdated router or phone firmware can cause Wi-Fi connection errors, including problems obtaining an IP address. Updates often fix bugs in DHCP and network protocols.

How to update your router firmware:

1. Open your router's control panel.
2. Find the section Software update, Firmware Update or System.
3. Check for updates and install them (do not turn off the router during the process!).

How to update your phone:

• Android: Settings → System → System Update.
• iPhone: Settings → General → Software Update.

⚠️ Attention: Updating your router's firmware may reset it to factory settings. Before updating, save your configuration (section Backup in the control panel).

After the update, restart both devices and try connecting to Wi-Fi.

What should I do if the router update failed?

If after the update the router does not turn on or works unstably, perform a factory reset (button Reset (on the back panel). Then configure it again. If the problem persists, contact the manufacturer's support—the firmware may be corrupted.

7. Check for viruses and third-party applications

Less often, but it happens that the error “Failed to obtain IP address” is caused by viruses or VPN/firewalls, which block network connections. Also, some "internet speed booster" or "Wi-Fi optimization" apps may conflict with system settings.

What to check:

• 🛡️ Antivirus: scan your phone for viruses (for example, Malwarebytes or Dr.Web).
• 🔒 VPN: disable VPN applications (eg. NordVPN, ProtonVPN) and check the connection.
• 📱 Third-party utilities: Remove or disable Wi-Fi management apps (e.g. Wi-Fi Master, NetOptimizer).

If Wi-Fi works after disabling the VPN or removing suspicious apps, the problem was with them. Add the network to your firewall exceptions or configure the VPN correctly.

Also check if it is turned on on your phone power saving mode - it can limit the operation of the Wi-Fi module. Android this is a setting Battery → Power Saving Mode, on iPhone — Settings → Battery → Low Power Mode.

FAQ: Frequently asked questions about the "Unable to obtain IP address" error

Could the problem be with the SIM card or mobile internet?

No, the "Unable to obtain an IP address" error only applies to Wi-Fi connections. Mobile internet (3G/4G/5G) uses a different IP address acquisition mechanism and does not affect Wi-Fi operation. However, if the "Unable to obtain an IP address" mode is enabled on your phone, Saving traffic or Background limitation, this may interfere with a stable Wi-Fi connection.

Why does the error only appear on one phone, while other devices connect normally?

This means the problem is localized to a specific phone. Possible causes:

• Incorrect network settings (e.g. static IP conflicting with other devices).
• Wi-Fi module failure (try turning it on/off) Airplane mode).
• MAC address conflict (if the router has blocked this MAC).
• Software errors (resetting network settings or updating software will help).

What to do if nothing helps?

If you have tried all the methods and the error persists, try the following:

1. Resetting the router to factory settings (button Reset for 10-15 seconds). Then set it up again.
2. Checking for hardware faults:
   • Try connecting your phone to a different Wi-Fi network (for example, at a cafe or at a friend's place). If the error persists, the problem is with your phone.
   • Try connecting another phone to your router. If it works, the problem is with the original phone.

Contacting the service center, if you suspect a malfunction of the phone's Wi-Fi module.

Is it possible to use the phone without fixing this error?

Yes, but with restrictions:

• You will be able to use mobile Internet (if configured).
• Some apps (such as instant messengers) will work over a mobile network, but this may cost more.
• Functions that require a local network (eg Smart TV, smart light bulbs), will be unavailable.

However, you shouldn't ignore the problem—it could indicate more serious problems with your phone or router.

Why does the error appear after updating Android/iOS?

OS updates sometimes change network protocol algorithms, which can lead to conflicts with router settings. For example:

• In new versions Android (starting with 10) the MAC address management policy has changed (they are now random for each network), which can confuse older routers.
• iOS sometimes tightens Wi-Fi security requirements (for example, refusing to connect to networks with outdated encryption) WEP).

Solution: Update your router firmware or reset your phone's network settings (see section 4).