Q：1. Confirm PPTP VPN settings: First, ensure that the PPTP VPN server is correctly set up on the Cellular Router and is in an active state. This includes verifying that the VPN server's IP address, port, username, and password are correctly configured.
2. Connect to the VPN: Using VPN client software that supports the PPTP protocol, establish a VPN connection with the Cellular Router on another device. This typically involves entering information such as the VPN server's IP address, port number, username, and password.
3. Access the internal network: Once the VPN connection is successfully established, your device will be able to access the internal network under the Cellular Router through the VPN tunnel. This means you can access other computers and devices connected to the Cellular Router.
4. Network access permissions: Please note that even with a VPN connection established, you still need to have appropriate network access permissions to access computers connected to the Cellular Router. This includes ensuring that the target computer's firewall settings allow access from the VPN connection and having the necessary user credentials (such as a username and password) to access the target computer.
5. Test the connection: After establishing the VPN connection, it is recommended to conduct a test to ensure successful access to computers connected to the Cellular Router. This can be done by attempting to access the target computer's shared folders, services, or using remote desktop connections.
Q：When the SIM card in the Cellular Router loses internet connection, you can try the following steps to troubleshoot the issue:
1. Check the SIM Card:
a. Confirm that the SIM card is correctly inserted into the SIM card slot of the Cellular Router and is not damaged or loose.
b. Check if the SIM card has expired or been deactivated. If so, contact your service provider for renewal or replacement.
2. Check Signal Strength:
a. Ensure that the Cellular Router is located in an area with stable mobile communication signals. If the signal is weak, try moving the Cellular Router to a location with stronger signal.
b. Consider replacing the SIM card with one that offers better signal coverage to improve the stability of the network connection.
3. Check Network Settings:
a. Log in to the management interface of the Cellular Router and check if the network settings and connection mode are correct.
b. Refer to the user manual of the Cellular Router or contact the manufacturer for support if needed to configure the network settings correctly.
4. Restart the Cellular Router:
a. Sometimes, a simple restart can resolve temporary network issues. Disconnect the power of the Cellular Router, wait for a few minutes, and then reconnect it.
5. Contact the Service Provider:
a. If the above steps fail to resolve the issue, it is recommended to contact the service provider of the SIM card to inquire about account status, package usage, and any known issues that may affect the network connection.
6. Check for Hardware Failures:
a. If you suspect hardware failures in the Cellular Router or the SIM card itself, consider replacing the Cellular Router or SIM card for testing.
7. Consider Other Factors:
a. Ensure that other devices (such as mobile phones, tablets, etc.) can normally use the internet in the same location to rule out the possibility of regional network failures.
b. Check if there are any other factors (such as weather, equipment malfunctions, etc.) that may affect the network connection.
Q：The external IP address of a 4G Cellular Router is dynamically changing, and it varies every time the connection is disconnected and reconnected. Therefore, I cannot provide a specific external IP address for a 4G Cellular Router.
It is important to note that unauthorized inquiries into others' IP addresses may infringe on their privacy and potentially violate relevant laws and regulations. Please abide by local laws, regulations, and ethical standards, respect the privacy rights of others, and refrain from attempting to illegally obtain or misuse others' IP addresses or other personal information.
Q：There can be various reasons why an industrial Cellular Router loses internet connection after IP configuration is completed. Here are some possible reasons and corresponding solutions:
1. IP address conflict: Ensure that the IP address configured for the Cellular Router does not conflict with the IP addresses of other devices in the network. Check the IP addresses of other devices in the network to ensure that the Cellular Router has a unique IP address.
2. Incorrect gateway configuration: The gateway is the device that connects the local network to other networks. If the gateway configuration is incorrect, the Cellular Router will not be able to access the external network normally. Ensure that the correct gateway address is configured for the Cellular Router.
3. DNS settings issue: DNS is responsible for converting domain names to corresponding IP addresses. If the DNS settings are incorrect, the Cellular Router will be unable to resolve domain names, resulting in no internet access. Check if the DNS settings are correct and try changing to other reliable DNS servers.
4. Physical connection issues: Ensure that the Cellular Router is properly connected to the modem (optical cat) and the computer. If using a wired connection, check if the network cable is securely plugged in. If using a wireless connection, ensure that the computer's wireless network card is enabled and connected to the correct wireless network.
5. Firewall settings: Check the firewall settings on the Cellular Router to ensure they do not block internet access. Try creating exceptions in the firewall or disabling the firewall to test the connection.
6. Firmware update: Outdated firmware on the Cellular Router may cause issues with internet connectivity. Log in to the Cellular Router's management interface to check if there are any available firmware updates. If there are, follow the prompts to update the firmware.
7. Broadband issues: Check if there are any problems with the broadband connection. Try connecting the broadband cable directly to the computer's Ethernet port and using the computer's broadband connection to see if you can access the internet. If you cannot connect to the internet, it indicates a problem with the broadband, and you should contact the broadband service provider for assistance.
Additionally, if you are using a 4G industrial Cellular Router, you also need to check if the SIM card is in arrears and if the "keep online" function has been correctly configured.
Q：The IP address of an industrial Cellular Router 4G is typically not fixed. Since the 4G Cellular Router connects to the internet through a mobile network, its IP address is dynamically allocated by the mobile network operator. Therefore, each time the Cellular Router connects to the network, it may obtain a different IP address. This dynamic allocation means that the IP address of an industrial Cellular Router 4G is not fixed.
If a fixed IP address is required for specific network applications or configurations, you can consider applying for a static IP address service from the mobile network operator. However, please note that this usually requires additional fees and may be subject to the operator's policies and availability.
Q：Configuring a VPN on a firewall to access a computer connected to a secondary Cellular Router typically involves a series of steps to ensure proper network connectivity and security settings. The following is a general guideline, but please note that specific steps may vary depending on your network environment and device models.
1. Configure VPN Settings on the Firewall:
① Log in to the firewall's management interface.
② Navigate to the VPN settings section and select the appropriate VPN type (e.g., L2TP, IPsec).
③ Configure the corresponding parameters based on the chosen VPN type, such as pre-shared keys, authentication modes, etc.
④ Ensure that the firewall allows VPN traffic and configure appropriate port forwarding or NAT rules.
2. Configure the Secondary Cellular Router:
① Log in to the management interface of the secondary Cellular Router.
② Enable VPN passthrough functionality (if available) to allow VPN traffic to traverse the secondary Cellular Router.
③ Configure routing rules to ensure that VPN traffic is routed correctly to the target computer.
3. Set up the VPN Client on the Target Computer:
① Install and configure a VPN client software on the device that needs to access the computer connected to the secondary Cellular Router.
② Enter the correct server address, username, and password based on the firewall's VPN settings.
③ Connect to the VPN server.
4. Test the Connection:
① Once the VPN connection is successfully established, you should be able to access the computer connected to the secondary Cellular Router through the VPN.
② Try accessing shared folders on the target computer or using remote desktop connection functionality to test the connection.
Please note that VPN configuration involves important aspects of network security and privacy protection. Ensure that you understand the associated security risks and take appropriate security measures, such as using strong passwords, regularly updating firmware and software, and limiting VPN access permissions.
