- April 10, 2015
- 2 条评论
16，google “free vpn”就会出现一大堆免费VPN账号的
- March 14, 2015
- 2 条评论
$ wget -c https://www.python.org/ftp/python/2.7.9/Python-2.7.9.tgz
$ tar zxvf Python-2.7.9.tgz
# cd Python-2.7.9 && ./configure && make && make install
! 1. 注意，这个是覆盖安装，如果有更多老版本需求，建议在configure 后面添加路径参数，如:–prefix=/usr/python27
2. use root to install it!
# curl -O https://bootstrap.pypa.io/get-pip.py # python get-pip.py
- March 8, 2015
- 0 条评论
Angry IP Scanner, also known as ipscan, is an open source network scanning tool that can be used to scan the ip addresses and ports on your network. It supports Linux, Windows, MAc OSX and other platforms. It has designed to be fast and simple to use. It has been used by Network administrators on almost all organizations.
- Lightweight and cross-platform.
– Scans ip addresses in any range.
– Doesn’t require any installation
– Check for ip address if it is alive.
– Resolves hostnames, determines ip addresses and scans ports.
– Multi-threaded support to speed up scanning process.
As i mentioned before, we don’t have to install it. All we need is our system should have installed with Oracle java or openjdk. Just download the ipscan jar file and run it with command:
# java -jar ipscan.x.x.jar
Also you can install it if you wish. Just download deb/rpm packages and install as described below.
Hence all modern operating system comes with openjdk in their default repositories, we don’t have to worry about openjdk installation.
First install openjdk using command:
$ sudo apt-get install openjdk-7-jdk
# yum install java-1.7.0-openjdk
Then grab Angry IP Scanner latest version from here depending upon your platform and architecture.
After downloading it, go to the directory where you have downloaded and install it using command:
$ sudo dpkg -i ipscan_3.2.1_*.deb
[[email protected] ~]# rpm -Uvh /ipscan-3.2.1-*.rpm
Launch Angry IP Scanner
After installing, launch it either from Menu or Dash. At the first launch, you’ll pleased with Getting Started screen. You can read it by clicking on the Next button or click Close to exit Getting Started screen.
Scan Local System
Let us start with local system ip address. Click Start to scan. After a couple of seconds, you will get the Scan Statistics like below.
In the above test, we scanned only single system, i.e I entered the the same ip address on IP Range boxes. Now let me scan some remote systems on my network. Say for example, let us scan systems whose has ip address between 192.168.1.100 to 192.168.1.110.
Enter ip addresses 192.168.1.100 and 192.168.1.110 in the from and to column boxes of IP Range and click Start button.
Now you’ll see the list of alive hosts in the range of network that you have entered.
Not only it displays the alive hosts in your network, also it will allow you to manage the remote systems. Let us see how.
Let us say you want to ssh to a system on your network. Just right click on the ip address, go to Open and select SSH. Alternatively you can open it from Menu bar. Click on the Commands button on the menu bar and go to Open -> SSH.
While testing this app, i found myself, it will be quite useful for Network administrators. It is simple, but powerful and it does the job as advertised. Hope it will be useful for you.
- March 8, 2015
- 1 条评论
Swap is a type of filesystem and is a virtual memory. Whenever your RAM is full, your operating system will look for further memory in your swap space. For this reason, you reserve some part of the hard disk to create a swap partition.
Identifying Current Swap Space Usage
[[email protected] ~]# cat /proc/swaps Filename Type Size Used Priority /dev/sda7 partition 1951740 4 -1
Alternatively, use the swapon command:
[[email protected] ~]# swapon -s Filename Type Size Used Priority /dev/sda7 partition 1951740 4 -1
Finally, the free command may also be used:
[[email protected] ~]# free total used free shared buffers cached Mem: 895112 721656 173456 0 36592 310156 -/+ buffers/cache: 374908 520204 Swap: 1952736 4 1952732
Adding a Swap File
Additional swap may be quickly added to the system by creating a file and assigning it as swap. This is achieved as follows. The following dd command example creates a swap file with the name swap with a size of 1Gb.
Create the swap file using the dd command:
[[email protected] ~]# dd if=/dev/zero of=/swap bs=1M count=1024 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 17.4283 s, 61.6 MB/s
Configure the file as swap
Change the permission of the swap file so that only root can access it
[[email protected] ~]# chmod 600 /root/swap [[email protected] ~]# mkswap /swap Setting up swapspace version 1, size = 1048572 KiB Enable the newly created swapfile : [[email protected] ~]# swapon /swap
Finally, modify the /etc/fstab file to automatically add the new swap at system boot time by adding the following line:
# cat /etc/fstab /swap none swap sw 0 0
Once the swap space has been activated, verify that it is in use using the swapon –s command:
[[email protected] ~]# swapon -s Filename Type Size Used Priority /dev/sda7 partition 1951740 142884 -1 /swap file 1048572 0 -2
[[email protected] ~]# free -k total used free shared buffers cached Mem: 895112 828484 66628 0 2144 539552 -/+ buffers/cache: 286788 608324 Swap: 3000312 142876 2857436
If you don’t want to reboot to verify whether the system takes all the swap space mentioned in the /etc/fstab, use following to enable or disable swap.
[[email protected] ~]# swapoff -a
[[email protected] ~]# swapon -a
De-activate the additional swap space at any time using the swapoff command as follows:
[[email protected] ~]# swapoff /newswap