Here, I'm going to block port no 80 (used by NGINX) in UFW (which is pre-installed in Ubuntu). First, let's check the status of UFW: sudo ufw status And if it showsinactive, you can use the given command to enable it: sudo ufw enable Now, you just have to pair thedenyoption...
In order to block IP using iptables , you can execute following commands up on your condition. If you want to block an ip address from accessing your server then type the commands as follows: iptables -A INPUT -s IP-ADDRESS -j DROP Example : iptables -A INPUT -s 10.10.10.10 -j DROP...
Typically, ports identify a specific network service assigned to them. This can be changed by manually configuring the service to use a different port, but in general, the defaults can be used. The first 1024 ports (port numbers0to1023) are referred to aswell-known port numbersand are reserv...
In this How to Make Tech Work tutorial, Jack Wallen shows how to add another layer of security to your Linux machines with just two files.
There are several ways to automatically configure networks in Linux-based systems. The most widely used option on desktops and notebooks is NetworkManager. Other network configuration management systems are mainly targeted for smaller embedded systems, such as OpenWRT’s netifd, Android’s ConnectivityMan...
The Linux kernel handles networking in a similar way to the SCSI subsystem described in Chapter 3. 计算机通过使用一系列组件来回答这些问题,每个组件负责发送、接收和识别数据的某个方面。 这些组件按照层次分组,堆叠在一起形成一个完整的系统。 Linux内核处理网络的方式与第三章中描述的SCSI子系统类似。
Block User Login in Linux How to Block User Logins Using nologin Shell This method works a little differently: it only blocks a user from accessing a shell. But he or she can log on to the system via programs such asftpthat do not necessarily require a shell for the user to connect ...
Moreover, Linux applications block a port for themselves whenever they communicate with their servers. It occupies a port for that process. For various reasons, you may sometimes need to terminate the process to save the storage and improve the system performance. However, if you do not know ...
Before you start blocking the IPs, you should first check your current iptables rules to make sure that you don’t accidentally block any valid traffic. Run the following command in the Linux terminal: $sudoiptables-L You should be able to see an output that is similar to the one in the...
Reject access with Linux route command Using iptables sometimes causes conflicts with installed firewalls so that I will use the route command here. The command is: route add -host 192.168.0.123 reject Replace 192.168.0.123 with the IP address that you want to block and execute the command as ...