Linux system upgrade configurations

Linux system upgrade configurations

1. Disable IPV6

Vi/etc/sysconfig/network

NETWORKING_IPV6 = no # Drop

Source/etc/sysconfig/network

 

Vi/etc/modprobe. conf

Add alias net-pf-10 off
Alias ipv6 off

2. Disable shutdown and restart permissions for normal users (control permissions)

Vi/etc/inittab

Comment out ca: ctrlaltdel;/sbin/shutdown-t3-rnow (disable hot start)

 

3. User Access Control (I did not use this operation for company reasons)

Vi/etc/hosts. deny

Add; ALL: ALL access from any IP address is not allowed

Vi/etc/hosts. allow

Sshd: 192.168.2.10 allows ssh logon with an IP address of 10

 

4. Modify the alias file

Vi/etc/aliases

Comment out the following content: games ingres system toor manager dumper decode root may contain operator

5. Disable PIN access and enter

Echo 1>/proc/sys/net/ipv4/icmp_echo_ignore_all

Change echo 1 to echo 0 for recovery.

 

6. Prohibit source routing (generally prohibited)

Echo 0>/proc/sys/net/ipv4/conf/all/accept_source_route
Echo 0>/proc/sys/net/ipv4/conf/default/accept_source_route
Echo 0>/proc/sys/net/ipv4/conf/eth0/accept_source_route
Echo 0>/proc/sys/net/ipv4/conf/eth1/accept_source_route
Echo 0>/proc/sys/net/ipv4/conf/lo/accept_source_route

7. Prevent SYN Attacks

Echo 1>/proc/sys/net/ipv4/tcp_syncookies

Linux configuration file

Generally, the configuration files are stored in the/etc directory (you can run the: ll/etc command to list the specific content in the etc directory)
Different services correspond to different files. For example:
/Etc/httpd. conf corresponds to apache service
/Etc/named. conf corresponding DNS Service
/Etc/dhcpd. coonf corresponding DHCP Service
/Etc/samba/smb. conf file sharing
/Etc/passwd User Name
/Etc/shadow User Password
/Etc/ypserv. conf corresponds to the NIS Service
/Etc/vsftpd. conf corresponds to the FTP service
Host Name and IP address relationship of/etc/hosts
Settings of the DNS server corresponding to/etc/resolv. conf
If you want to modify the configuration file, you can modify it based on your actual needs! However, the location of some files cannot be modified!

Linux application and network configuration

What is Linux?
To put it simply, Linux is a free-of-charge and freely-spread Unix-like operating system, which is mainly used on Computers Based on Intel x86 series CPUs. This system is designed and implemented by thousands of programmers around the world. The purpose is to establish a Unix-compatible product that is free of copyright control from any commercialized software and available worldwide. Linux was first introduced to a computer hobbyist named Linus Torvalds, who was a student at Helsinki University in Finland. He aims to design an operating system that replaces Minix (an operating system teaching program compiled by a computer professor Andrew Tannebaum, this operating system can be used on 386, 486, or Pentium processor PC, and has all the functions of the Unix operating system, thus starting the design of the Linux prototype. Linux is famous for its efficiency and flexibility. It can implement all Unix features on PC computers and has the ability of multi-task and multi-user. Linux is a POSIX-compliant operating system that is obtained free of charge under the GNU Public License. The Linux operating system package includes not only the complete Linux operating system, but also text editor, advanced language compiler, and other application software. It also includes an X-Windows graphical user interface with multiple Window managers. Like using Windows NT, it allows us to operate the system using Windows, icons, and menus.
What is the difference between Linux and other operating systems:
Linux can coexist with other operating systems such as MS-DOS, OS/2, and Windows on the same machine. They are all operating systems and have some commonalities, but they are distinctive and different from each other.
Currently, the operating systems running on PCs mainly include Microsoft's MS-DOS, Windows, Windows NT, and ibm OS/2. Early PC users generally use MS-DOS, because this operating system does not require high hardware configuration, and with the rapid development of computer hardware technology, the price of hardware equipment is getting lower and lower, people can easily improve computer hardware configuration, so they began to use Windows, Windows NT and other graphic operating systems. Linux is a new operating system that has attracted more and more attention. It is gradually accepted by PC users. So what are the main differences between Linux and other operating systems? The following two aspects are discussed.
First, let's take a look at the differences between Linux and MS-DOS. Running Linux and MS-DOS on the same system has been very common, to play the processor function, the MS-DOS does not fully implement the x86 processor function, and Linux runs completely in the processor protection mode, all features of the processor are developed. Linux can directly access all available memory in the computer and provide a complete Unix interface. While MS-DOS only supports some Unix interfaces.
In terms of cost of use, Linux and MS-DOS are two completely different entities. Compared with other commercial operating systems, MS-DOS is cheaper, and has a large share in PC users, any other PC operating system is difficult to reach the popularity of MS-DOS, because the cost of other operating systems is a great burden for most PC users. Linux is free of charge. You can obtain the version from the internet or other means, and you can use it as needed without considering the cost. MS-DOS is a single-task operating system, and once the user runs an MS-DOS application, it excludes the resources of the system, you cannot run other applications at the same time. Linux is a multi-task operating system. You can run multiple applications at the same time. Let's take a look at the differences between Linux and OS/2, Windows, and Windows NT.
From the back of development ...... The Rest Of The full text>