Cloud Applications

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

Scenario: locally deploy tomcat to port 8080, and expect local access to port 80 to access local tomcat. Conclusion: The iptables tool in linux is used to implement port forwarding. Specifically for the current get root permission to execute

Yesterday, I received a task where one network card (intranet/multiple network cards) on a server cannot communicate with other servers. I want to confirm the problem. In other words, I have never been exposed to such problems. I don't know how to

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

The first type keyword mainly includes host, net, port, such as host210.27.48.2, specifying 210.27.48.2 as a host, net202.0.0.0 specifying 202.0.0.0 as a network address, and port23 specifying port number as 23. If no type is specified, the default

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

HP-UX (HP-UX tutorial), all known as HewlettPackardUniX, is the operating system of HP 9000 Series servers that can run on HP's HP-UX11iv3 third-time upgrade PA-RISC processor, Intel's Itanium processor computer. It is based on SystemV and is a

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

You can also configure the shared directories of NFS and SMB through 'fstab. Because the options involved are very important and you need to understand the work of some protocols, you must first read Samba and NFS. There are not many differences

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.

Some examples of packet capture analysis have been found for a long time, which can be repeated continuously. After analyzing the packet capture, I think the basic skills are too inadequate. there are too many things involved and too many things to

The content of linux/etc/fstab mainly includes six items: for example, the following two lines: LABEL/ext3defaults11/dev/sda2/mnt/D/vfatdefaults00 first column: device Name or device volume name (/dev/sda10 or LABEL/) column 2: Device Mount

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