There are several proven methods for unblocking a Counter-Strike server. Many of them are based on changing the parameters of your own network card.
Necessary
Counter-Strike
Instructions
Step 1
The method for solving the problem directly depends on the type of blocking that was applied to your account. If you are banned "by nickname", then just restart the game and change the game nickname by typing the command name newnick in the console. Now you can safely play on the selected server.
Step 2
If you are blocked based on the value of your IP-address, then you can access the server only if your provider uses the issuance of dynamic IP-addresses to clients. Disconnect your internet connection. Wait a while (1-2 minutes).
Step 3
Reconnect to the internet. Make sure the system has given you a new IP address. To do this, open the properties of the network connection and go to the "Details" item. Try to log into the required server again, having previously changed your nickname.
Step 4
If you were blocked using the "MAC address" ban method, then change its value. This can only be done if your ISP does not use checking the MAC addresses of clients when connecting. Open the "Start" menu and go to the properties of the item "My Computer". Select the Device Manager menu.
Step 5
Find your network card through which you connect to the Internet. Right-click on its name and select "Properties". Now open the "Advanced" tab.
Step 6
Highlight the "Network Address" item. Press the Start + R key combination. Type cmd in the new field. Type ipconfig / all from the menu that opens. Find the value of the MAC address of this network card. Enter it in the network adapter properties menu field, replacing one letter or number. Click the "Ok" button. Wait for the network adapter settings to be applied.
Step 7
If you use a Steam account to play Counter-Strike and the blocking is based on denying access to this particular account, then you just have to play non-steam on this server.