For the problems you raised, the following are the possible causes and solutions:

1、 Possible causes

1. Broadband or optical fiber problems:
? ?- Broadband arrearage may lead to network instability or inability to connect.
? ?- External line failures, such as fiber breakage or fiber suspension, will affect the stability of the network.
? ?- The connection problem between the optical cat and the optical fiber, such as poor contact or disconnected interface, may also lead to network abnormalities.

2. Router failure:
? ?- The router may have a hardware failure or software problem that affects its normal function.
? ?- A router running for a long time may generate garbage files, which may cause slow operation or crash.

3. Computer network settings or hardware problems:
? ?- There may be a problem with the network card driver of the computer, which prevents it from connecting to the network properly.
? ?- Incorrect network settings, such as IP address and DNS server configuration errors, will also affect network connectivity.

2、 Solution

1. Check the broadband and optical fiber status:
? ?- Confirm whether the broadband is in arrears. If there is any arrears, please pay in time.
? ?- Check whether the optical fiber line is in good condition. If it is damaged, please contact the maintenance personnel for repair.
? ?- Check whether the connection between the optical cat and the optical fiber is firm. If there is any problem, please reconnect or contact the maintenance personnel for handling.

2. Restart the router and optical cat:
? ?- Try restarting the router and the optical cat to clear the temporary cache and garbage files and restore them to normal operation.
? ?- If the problem still exists after restarting, please consider replacing the router or contacting the manufacturer for maintenance.

3. Check and set up the computer network:
? ?- Update or reinstall the network card driver of the computer to ensure that the hardware works properly.
? ?- Check and adjust the network settings to ensure that the IP address and DNS server are configured correctly.
? ?- Try disabling and re enabling the network connection, or reset the network settings to restore the network connection.

To sum up, the router red light is always on mobile phone The problem of being able to connect to the Internet while the computer sometimes fails to connect to the Internet may involve many aspects. It is recommended to check and solve the problems one by one according to the above steps. If the problem still cannot be solved, please contact professional network maintenance personnel for inspection and maintenance.