Cloud Applications

After CentOS is installed, only port 22 is enabled by default. if you want to open other ports, you need to open the required ports. For example, open the default port 80 for http edit iptablesvi/etc/sysconfig/iptables

Run the following command: # enable port 80 iptables-IINPUT-ptcp-mstate -- stateNEW -- dport80-jACCEPT # save modification serviceiptablessave # restart serviceiptablesrestart # view the status serviceiptablesstatus note: in/etc/sysconfi Run the

This section describes iptables concepts and usage instructions in iptables, which must be case sensitive. The main syntax differences between ipchains and iptables are as follows: 1. in ipchains, for example, the input chain uses lower-case chains.

We are already in the borderless network age. Are you confused? What is a borderless network? What is the difference between a borderless network and a previous network ?...... 1. enable the firewall and disable/etc/init for unnecessary ports.

In the previous blog, I explained some common knowledge about iptable. here I will repeat the linux firewall with two parts, they are netfilte in the kernel space and iptables in the user space, while iptable can define four types of rules: filter:

# Check whether the iptables command is/sbin/iptables [root @ test ~] # Whereisiptablesiptables:/sbin/iptables/usr/share/man/man8/iptables.8.gz # iptables has several default table tables, including filter, nat, and mangle # Initialize fil #

IPsecVPN data transmission process the following is a packet transmission process (such as ICMP packet) through the IPsecVPN tunnel ), when the PC in the subnet is protected by the VPN on the left to transmit data to the PC in the VPN on the right

The most common method for setting automatic service startup is in rc. add a script similar to the following in local: # sshd/usr/local/sbin/sshd # proftpd/usr/local/sbin/proftpd # apache/home/apache/bin/apachectlstart #

Some time ago, because I had to write a router program myself, I began to learn libpcap and netlink. I also read articles written by many cool people on the Internet, we found that the pcap and netlink materials in Chinese are quite few (in

Improper MTU settings may cause many network problems, such as the unavailability of some network applications and the unavailability of some websites. The following are the MTU settings that have been searched online. some of them may not be

The command to disable the firewall in Linux. today, I want to take a break from the ssh remote connection port on the LInux server for security purposes, I added a line of port8081 to the sshd_config file, but after the configuration is completed

Functions of the text editor: 1. create or modify a text file 2. maintain the classification of various configuration file text editors in linux: line editor and full screen editor, character interface editor and graphical interface editor the most

The file/etc/fstab contains static file system information and defines how storage devices and partitions are integrated into the entire system. The mount command reads the file and determines the mounting options for the device and partition. File

Kaiwii summarized my own experience in using vi or vim: First, move the cursor up and down: of course, use the arrow keys on the keyboard. (ps: What r, it is a pain to use vi. why should we remember so many commands ?) Simply remember one. press the

On the recently installed suseenterprise10, vim is still the default setting, which is very difficult to use. it took a night to complete the configuration, and sent a lot of information from the Internet, make a backup later ~~ Vim version: 7.3.

Description of LVM Logical Volume Creation and Expansion: PV: physical volume VG: volume group (a VG on the physical layer is composed of one or more PVs) LV: logical volume (a VG on the logical level is composed of one or more LV) the order of

In addition to basic commands, the init function of busybox also supports the init function. Like other init functions, the init function of BusyBox also completes system initialization and pre-shutdown, we know that after the Linux kernel is loaded,

1. The/etc/hostsfilemustcontainthefollowinginformation.127.0.0.1localhost. localdomainlocalhost # Public192.168.2.101rac1. localdomainrac1191_2.102rac2. localdoma 1. The/etc/hosts file must contain the followinginformation. 127.0.0.1 localhost.

Usually there are two conditions for OOM: 1. no more pages can be allocated in the VM (note that linuxkernel delays page allocation policies and alloc only when used; therefore, malloc + memset is valid ). 2. insufficient user address space. in this

I have never been very familiar with LVM partitioning before. today it seems that I have to go through this link and paste the information I found on the Internet: # fdisk-l [root @ localhost/] # fdisk-lDisk/dev/sda: 36.7 GB,