Troubleshooting

2 Make sure the power adapter is connected to the Zyxel Device and plugged in to an appropriate power source. Make sure the power source is turned on.

3 Disconnect and re-connect the power adapter to the Zyxel Device.

4 Make sure you have pressed the POWER button to turn on the Zyxel Device.

5 If the problem continues, contact the vendor.

The LED does not behave as expected.

1 Make sure you understand the normal behavior of the LED.

2 Check the hardware connections.

3 Inspect your cables for damage. Contact the vendor to replace any damaged cables.

4 Turn the Zyxel Device off and on.

5 If the problem continues, contact the vendor.

Device Access Problems

I do not know the IP address of the Zyxel Device.

1 The default IP address is 192.168.1.1.

2 If you changed the IP address, you might be able to find the IP address of the Zyxel Device by looking up the IP address of your computer’s default gateway. To do this in Microsoft Windows, click Start > Run, enter cmd, and then enter ipconfig. The IP address of the Default Gateway might be the IP address of the Zyxel Device, depending on your network environment.

3 If this does not work, reset the Zyxel Device to its factory defaults.

• Locate a small hole labeled RESET on the Zyxel Device.

• Use a paperclip or a similar tool to press and hold the RESET button for more than 5 seconds.

• Release the button, and the Zyxel Device will reset to its default settings, including the default IP address, user name, and password.

Resetting the Zyxel Device will erase all your custom settings, so you need to reconfigure it.

I forgot the admin password.

1 See the Zyxel Device label or this document’s cover page for the default admin password.

2 If you changed the password from default and cannot remember the new one, you have to reset the Zyxel Device to its factory default settings.

I cannot access the Web Configurator login screen.

1 Make sure you are using the correct IP address.

• The default IP address is 192.168.1.1.

• If you changed the IP address, use the new IP address.

• If you changed the IP address and have forgotten the new address, see the troubleshooting suggestions for I do not know the IP address of the Zyxel Device.

2 Check the hardware connections, and make sure the LEDs are behaving as expected.

3 Make sure your Internet browser does not block pop-up windows and has JavaScript and Java enabled.

4 Clear the Internet browser cache and try accessing the Web Configurator login screen again. Outdated browser data can cause login issues. If the problem persists, try logging into the Web Configurator using a different browser. (For example, Chrome, Firefox, Edge.)

5 If it is possible to log in from another interface, check the service control settings for HTTP and HTTPS (Maintenance > Remote Management).

6 Reset the Zyxel Device to its factory default, and try to access the Zyxel Device with the default IP address.

7 If the problem continues, contact the network administrator or vendor, or try one of the advanced suggestions.

Advanced Suggestions

• Make sure you have logged out of any earlier management sessions using the same user account even if they were through a different interface or using a different browser.

• Try to access the Zyxel Device using another service, such as Telnet. If you can access the Zyxel Device, check the remote management settings and firewall rules to find out why the Zyxel Device does not respond to HTTP.

I cannot log into the Zyxel Device.

1 For first-time Zyxel Device logins, after using the label password to access the Web Configurator, ensure your new password meets the requirements on the screen. For example, some models require the new password to be at least 8 characters long and include at least one uppercase letter, one lowercase letter, one number, and one special character.

2 Make sure you have entered the user name and password correctly. The default user name is . These both user name and password are case-sensitive, so make sure [Caps Lock] is not on.

3 You cannot log in to the Web Configurator while someone is using Telnet to access the Zyxel Device. Log out of the Zyxel Device in the other session, or ask the person who is logged in to log out.

4 Turn the Zyxel Device off and on.

5 If this does not work, you have to reset the Zyxel Device to its factory default. To reset the Zyxel Device, press the RESET button until the POWER LED begins to blink and then release it.

I cannot log into the Zyxel Device using DDNS.

If you connect your Zyxel Device to the Internet and it uses a dynamic WAN IP address, it is inconvenient for you to manage the Zyxel Device from the Internet. The Zyxel Device’s WAN IP address changes dynamically. Dynamic DNS (DDNS) allows you to access the Zyxel Device using a domain name.

To use this feature, you have to apply for DDNS service at www.dyndns.org.

If you have a private WAN IP address, then you cannot use DDNS.

Here are the three steps to use a domain name to log in the Web Configurator:

Step 1 Register for a DDNS Account on www.dyndns.org

1 Open a browser and enter http://www.dyndns.org.

2 Apply for a user account. This tutorial uses UserName1 and 12345 as the username and password.

3 Log into www.dyndns.org using your account.

4 Add a new DDNS host name. This tutorial uses the following settings as an example.

• Hostname: zyxelrouter.dyndns.org

• Service Type: Host with IP address

• IP Address: Enter the WAN IP address that your Zyxel Device is currently using. You can find the IP address on the Zyxel Device’s Web Configurator Status page.

Then you will need to configure the same account and host name on the Zyxel Device later.

Step 2 Configure DDNS on Your Zyxel Device

Configure the following settings in the Network Setting > DNS > Dynamic DNS screen.

• Select Enable Dynamic DNS.

• Select www.DynDNS.com as the service provider.

• Enter zyxelrouter.dyndns.org in the Host Name field.

• Enter the user name (UserName1) and password (12345). Click Apply.

Step 3 Test the DDNS Setting

Now you should be able to access the Zyxel Device from the Internet. To test this:

1 Open a web browser on the computer (using the IP address a.b.c.d) that is connected to the Internet.

2 Enter http://zyxelrouter.dyndns.org and press [Enter].

3 The Zyxel Device’s login page should appear. You can then log into the Zyxel Device and manage it.

I cannot connect to the Zyxel Device using Telnet, SSH, or Ping.

1 See the Remote Management section for details on allowing web services (such as HTTPS, Telnet, SSH and Ping) to access the Zyxel Device.

2 Check the server Port number field for the web service in the Maintenance > Remote Management screen. You must use the same port number in order to use that web service for remote management.

3 Try the troubleshooting suggestions for I cannot access the Web Configurator login screen. Ignore the suggestions about your browser.

I cannot access the Zyxel Device from outside the network (WAN).

To test if this is due to CGNAT, follow these steps:

1 Log in to your Zyxel Device’s Web Configurator using the default IPv4 address (for example, 192.168.1.1).

2 Locate the WAN IP address on the Dashboard screen. You can find this information in the Network or WAN settings.

3 Go to a website that can show you the public IP address of your network (for example, https://whatsmyip.com). When you access this site, it will display your public IP address.

4 Compare the WAN IP address displayed on the Dashboard screen with the public IP address shown on the https://whatsmyip.com website.

• If both IP addresses are the same, your ISP is not using Carrier-Grade NAT, and you should be able to access your Zyxel Device from the WAN (outside).

• If the IP addresses are different, it indicates that your ISP is using Carrier-Grade NAT, and your Zyxel Device has a shared public IP address. As a result, remote access to your Zyxel Device from the WAN will not be possible.

If you discover that your Zyxel Device is behind a Carrier-Grade NAT and you need remote access, you must contact your ISP and request a public IP address for your SIM card or Zyxel Device.

I need more than one account on my Zyxel Device.

To let multiple users access the Web Configurator, you can create more than one Administrator or User account. A total of eight users can log in to the Zyxel Device at the same time.

The total number of accounts you can create for each group type:

Administrator Account	4
User Account	4

Follow the steps below to create Administrator or User accounts:

1 Log in to the Web Configurator. Go to Maintenance > User Account. Click the

icon on the right to Add New Account.

2 Enter the information for the new account in the appropriate fields. In the Group drop-down list, select Administrator or User to assign different privileges to the account. For more details about the privileges of Administrator and User accounts, please refer to User Account. Click OK.

3 In the Maintenance > User Account screen, the newly created account will be displayed. Click Apply to save the new accounts.

Internet Problems

I cannot access the Internet.

1 Check the hardware connections and make sure the LEDs are behaving as expected. See the Quick Start Guide.

2 Make sure you entered your ISP account information correctly on the Network Setting > Broadband screen. Fields on this screen are case-sensitive, so check if [Caps Lock] is on of off.

3 If you are trying to access the Internet wirelessly, make sure that you enabled the Wi-Fi in the Zyxel Device and your Wi-Fi client and that the Wi-Fi settings in the Wi-Fi client are the same as the settings in the Zyxel Device.

4 Disconnect all the cables from your Zyxel Device and reconnect them.

5 If the problem continues, contact your ISP.

How to verify if my WAN connection is active?

1 Check the WAN LED indicator on the Zyxel Device to see if the WAN connection is active.

2 Log into the Web Configurator. In Connection Status, if the WAN connection is down, the WAN Status field displays Connection down. If there is an active WAN connection, the WAN Status field shows the type and speed of the connection. For example, Ethernet WAN 1000/Full means the Zyxel Device’s Ethernet WAN link speed is 1000 megabits per second (1 Gbps) in full duplex mode. Full duplex means the Zyxel Device can transmit and receive data at the same time.

3 If you use the Zyxel One app to manage the Zyxel Device, you can view the status of the Zyxel Device in the Home page. When the connection is active, the status shows Online with a solid green circular icon. For cellular connections, the Home page displays 4G or 5G connection with a solid green signal icon.

If the connection is down, the status will display Offline in the Home page.

I cannot connect to the Internet using an Ethernet connection.

1 Make sure you have the Ethernet WAN port connected to a Modem or Router.

2 Make sure you configured a proper Ethernet WAN interface (Network Setting > Broadband screen) with the Internet account information provided by your ISP and that it is enabled.

3 Check that the WAN interface you are connected to is in the same interface group as the Ethernet connection (Network Setting > Interface Group).

4 If you set up a WAN connection using bridging service, make sure you turn off the DHCP feature in the Network Setting > Home Networking > LAN Setup screen to have the clients get WAN IP addresses directly from your ISP’s DHCP server.

I cannot connect to the Internet using a Fiber connection.

1 Make sure the Fiber/SFP port has a compatible SFP/SFP+ transceiver installed with a fiber/Ethernet cable connected to it.

2 Check the hardware connections, and make sure the LEDs are behaving as expected. See the Quick Start Guide.

The PON LED is off if the optical transceiver has malfunctioned or the fiber cable is not connected or is broken or damaged enough to break the PON connection.

The LOS LED is red if the GPON Device is not receiving an optical signal.

The LOS LED blinks red if the GPON Device is receiving a weak optical signal.

3 Disconnect all the cables from your device and reconnect them. Make sure the fiber cable is not curved too much.

4 If that does not work, restart your Zyxel Device.

5 If the problems continues, contact your ISP.

I cannot connect to the Internet using a cellular connection.

1 The DSL and Ethernet connections have priority in that order. If the DSL or Ethernet connection is up, then the cellular connection will be disabled.

2 Make sure you have connected a compatible cellular dongle to the USB port, if required.

3 Make sure you have configured Network Setting > Broadband > Cellular Backup correctly.

• If the cellular dongle supports PIN codes, ensure the SIM card’s PIN code is entered in the PIN field in Network Setting > Broadband > Cellular Backup > Cellular Connection Settings.

• In Network Setting > Broadband > Cellular Backup > Cellular Connection Settings, select Obtain an IP Address Automatically if your ISP did not assign a fixed IP address to the SIM card in your cellular dongle.

4 Check that the Zyxel Device is within range of a cellular base station. To check local 3G, 4G, and 5G network coverage, you can use the nPerf website. Select your country, choose your carrier, and enter your address. You can also ask your ISP about the availability of 3G, 4G, and 5G signals in your area.

5 Make sure the SIM card in the cellular dongle is not damaged, is properly seated in the SIM slot, and has an active data plan. If the SIM card has exceeded its data limit, the ISP may reduce the network speed or stop data transmission until you pay the fee or purchase additional data.

6 Check with your ISP to ensure that the cellular base station is not experiencing network outages due to disasters, signal interference, or maintenance.

7 If the location where you set up the Zyxel Device has too many users, it may cause network congestion and lead to disconnection.

The Zyxel Device cannot assign individual IP addresses to the connected client devices.

1 Make sure to select Bridge in Network Setting > Broadband > Add/Edit New WAN Interface: Mode.

2 Make sure to reboot the Zyxel Device after changing to Bridge mode.

3 Make sure the Zyxel Device can get an IP address dynamically (DHCP) from the router controller.

The Internet connection is slow or intermittent.

1 There might be a lot of traffic on the network. If the Zyxel Device is sending or receiving a lot of information, try closing some programs that use the Internet, especially peer-to-peer applications.

2 If your Zyxel Device keeps alternating between ISPs, then choose a fixed ISP. Go to the Network Setting > Cellular PLMN screen, disable PLMN Auto Selection and then choose your preferred ISP.

3 Turn the Zyxel Device off and on.

4 If the problem continues, contact the network administrator or vendor, or try the advanced suggestions in I cannot access the Web Configurator login screen.

If your Zyxel Device is an outdoor-type, inclement weather like rain and hot weather may affect cellular signals.

What should I do if my Zyxel Device is under attack?

A slow Internet speed, a web browser that keeps redirecting you, suspicious activity alerts from your ISP, and increased pop-ups on the Zyxel Device; could be signs that your Zyxel Device is under attack. If you suspect that your Zyxel Device is under attack, do the following:

1 Create an ACL (Access Control List) rule to block the ports being targeted. See Access Control (Rules) for more information on using ACL. See also Configure a Firewall Rule for more information on configuring a firewall rule. Go to System Monitor > Log > Security Log to view the security-related logs to determine which ports are being targeted. See Security Log for more information on security logs.

2 Contact your ISP to report the attack and seek assistance.

3 When possible, turn off the Zyxel Device for 24 hours, then turn it on again.

4 Request the ISP to change your IP address.

Wi-Fi Problems

I cannot connect to the Zyxel Device Wi-Fi.

1 Check the Wi-Fi LED status to make sure the Zyxel Device Wi-Fi is on.

2 Make sure your Wi-Fi client is within transmission range of the Zyxel Device.

3 Make sure you entered the correct SSID and password. See the Zyxel Device back label for the default SSID and password.

4 Make sure your Wi-Fi client is using the same Wi-Fi security type (WPA2-PSK, WPA3-SAE, or none) as the Zyxel Device.

5 Make sure the Wi-Fi adapter on your Wi-Fi client is working properly. Right-click your computer's network adapter then select Properties to check your network adapter status.

6 Make sure the Wi-Fi adapter on your Wi-Fi client is IEEE 802.11-compatible and supports the same Wi-Fi standard as the Zyxel Device radio.

To check if it is your Zyxel Device that is causing the problem and not your Wi-Fi connection, try using a wired connection.

The Wi-Fi connection is slow and intermittent.

The following factors may cause interference:

• Obstacles: walls, ceilings, furniture, and so on.

• Building Materials: metal doors, aluminum studs.

• Electrical devices: microwaves, monitors, electric motors, cordless phones, and other wireless devices.

To optimize the speed and quality of your Wi-Fi connection, you can:

• Move your wireless device closer to the AP if the signal strength is low.

• Reduce wireless interference that may be caused by other Wi-Fi networks or surrounding wireless electronics such as cordless phones.

• Place the AP where there are minimum obstacles (such as walls and ceilings) between the AP and the Wi-Fi client.

• Reduce the number of Wi-Fi clients connecting to the same AP simultaneously, or add additional APs if necessary.

• Try closing some programs that use the Internet, especially peer-to-peer applications. If the Wi-Fi client is sending or receiving a lot of information, it may have too many programs open that use the Internet.

• Place the Zyxel Device where there are minimum obstacles (such as walls and ceilings) between the Zyxel Device and the Wi-Fi client. Avoid placing the Zyxel Device inside any type of box that might block Wi-Fi signals.

I can’t find my Zyxel Device’s Wi-Fi network name (SSID).

To easily identify your Zyxel Device’s Wi-Fi network among the available networks, you can change the default Wi-Fi network name.

To modify the Wi-Fi network name:

• Log into the Web Configurator.

• Go to Network Setting > Wireless > General.

• In Wireless Network Settings, enter the new Wi-Fi network name in the Wireless Network Name field. You can use up to 32 printable characters, including spaces.

• When finished, scroll down and click Apply.

Your new Wi-Fi network name is now set.

I want to allow or block specific devices from connecting to the Zyxel Device’s Wi-Fi network.

MAC authentication allows devices with MAC addresses listed in the Zyxel Device’s MAC address list to connect or block access to its Wi-Fi network.

To set up MAC authentication of your Zyxel Device, follow the steps below:

1 Log into your Zyxel Device’s Web Configurator, and go to Network Setting > Wireless > MAC Authentication.

2 In the General section, select the SSID of the Wi-Fi network for which you want to configure MAC authentication from the drop-down list.

3 There are two ways to configure the MAC authentication:

3a Set the MAC addresses you want to block access to the Zyxel Device’s Wi-Fi network.

• In the MAC Restrict Mode section, select Deny.

• In the MAC address list section, click the

icon to add a new MAC address.

• The Add MAC address to list screen will appear. In the MAC Address field, enter the MAC address you want to block access to the Zyxel Device’s Wi-Fi network.

3b Set the MAC addresses you want to allow to connect to the Zyxel Device’s Wi-Fi network.

• In the MAC Restrict Mode section, select Allow.

• In the MAC address list section, click the

icon to add a new MAC address.

• The Add MAC address to list screen will appear. In the MAC Address field, enter the MAC address you want to allow to connect to the Zyxel Device’s Wi-Fi network.

I blocked a smartphone using the MAC Authentication screen, but it can still access the Zyxel Device’s Wi-Fi network. Why?

Nowadays, many smartphones use a private (randomized) MAC address for each Wi-Fi network instead of the device’s actual MAC address.

To block a smartphone effectively, you need to find the private MAC address it uses for the specific Wi-Fi network. Follow the steps below to locate it:

1 For iOS devices, go to Settings > Wi-Fi, click the information icon next to the Wi-Fi network you want to block.

2 Look for the Wi-Fi Address. This is the private MAC address that the smartphone is using to connect to that Wi-Fi network. Add this address to the MAC Authentication deny list to block the device.

My notebook stays connected to the 2.4 GHz Wi-Fi network even though the Zyxel Device also supports 5 GHz.

To solve this issue, enable Keep the same settings for 2.4GHz and 5GHz wireless networks.

This setting allows the 2.4 GHz and 5 GHz Wi-Fi bands to share the same network name (SSID) and some security settings. Your notebook can seamlessly connect to the optimal band based on signal strength and its specifications. The Zyxel Device intelligently connects the notebook to the best available band for optimal performance and coverage:

• 2.4 GHz: better range and slower speed

• 5 GHz: faster speed and shorter range

• 6 GHz (if supported): very fast but with the shortest range

To see if your model supports 6 GHz, please see Overview for more information.

To do this, follow the steps below:

1 Log in to the Web Configurator.

2 Go to Network Setting > Wireless > General, and click the Keep the same settings for 2.4GHz and 5GHz wireless networks switch

to the right.

3 Click Apply.

Your notebook should now automatically connect to the best available band for optimal performance.

Mesh Problems

I can’t build a mesh network between the Zyxel Device and the extender(s).

Different mesh technologies may be incompatible, so make sure the Zyxel Device and the extender(s) use the same mesh technology.

To build a mesh network and ensure the smooth client roaming between the Zyxel Device and the extender(s), please check the following.

1 Make sure the Zyxel Device and the extender(s) have consistent SSID and security settings.

2 Make sure the Zyxel Device and the extender(s) are not too far or too close to each other.

USB Problems

The Zyxel Device fails to detect my USB device.

1 Disconnect the USB device.

2 Reboot the Zyxel Device.

3 If you are connecting a USB hard drive that comes with an external power supply, make sure it is connected to an appropriate power source that is on.

4 Reconnect your USB device to the Zyxel Device.

VoIP Problems

I cannot make phone calls through the phone connected to the Zyxel Device.

1 Pick up the phone and check the phone tone. You should hear the dial tone if your configuration on the Zyxel Device is correct, and your phone is successfully connected to the SIP server.

2 Check that the settings from your VoIP service are entered correctly on the Zyxel Device.

3 Make sure your phone is connected to the Zyxel Device phone port through an RJ-11 cable. Check the Zyxel Device phone LED for the corresponding phone status.

4 Make sure the Zyxel Device has an Internet connection. See Internet Problems for more information.

5 Make sure your SIP account is registered and your SIP service plan is valid. Use the System Monitor > VoIP Status screen to check the account Registration status.

6 Make sure your SIP server settings (in the VoIP > SIP > SIP Service Provider and the VoIP > SIP > SIP Account screens) use the correct information from your SIP service provider. For example, your SIP service provider name, SIP account and password.

7 Make sure your phone settings (in the VoIP > Phone > Phone Device screen) are correct.

8 Contact the SIP server administrator and make sure your SIP server is not down.

I am experiencing echoes during calls.

Go to VoIP > SIP > SIP Account > SIP Account Entry Edit. Click Enable G.168 (Echo Cancellation) to eliminate echo during calls.

UPnP Problems

My computer cannot detect UPnP settings from the Zyxel Device.

1 Make sure that UPnP is enabled in your computer.

2 On the Zyxel Device, make sure that UPnP is enabled on the Network Settings > Home Networking > UPnP screen.

3 Disconnect the Ethernet cable from the Zyxel Device’s Ethernet port or from your computer.

4 Reconnect the Ethernet cable.

5 Restart your computer.

Getting More Troubleshooting Help

Search for support information for your model at https://service-provider.zyxel.com/global/en/tech-support and community.zyxel.com for more troubleshooting suggestions.