Examples of Ping Command

-
Ping command is used to check the network status between two nodes.

Developed by : Mike Muss

Abbreviation : Packet INternet Grouper

How it Works : Ping works by sending an ICMP Echo Request(Type 8) packet to the other node specifying that Iam Alive and asking about his status,if the other node receives the packet he will reply with an ICMP Echo Reply(Type 0) packet telling the node he is also Alive.

With this ICMP messages Ping gives us the time that takes to reach and get back the reply from a node(round trip time).

Syntax : ping <ip_address>

Example : ping 192.168.1.5

We will see different examples in which we can use ping


1.Setting the Interval:
     
       By default ping sends an Echo Request for every one second. If you want to change the interval you can do it by specifying with 'i' option. If you want to have anything beyond 200 ms you have to be in root permissions

      Suppose if we want to send an ICMP Echo Request every 500 ms then we have to use the following command:

        ping -i 0.5 192.168.1.5


2. Setting the Number of Packets :

      By default ping continuously sends the ICMP messages until you stop it by sending a signal(CTRL+C). Suppose if you want to ping to send only N number of packets,you will use the 'c' option

Eg: You want the ping to send only 25 packets

    ping -c 25 192.168.1.5


3. Setting the Packet Size:

   Whenever you do a ping command he will send the ICMP packet with 56 bytes of data. If you want to modify this,you can do it with the 's' option

Eg: For sending an Ping packet with 20 bytes

    ping -s 20 192.168.1.5

But in the ouptut you are going to see

28 bytes from 192.168.1.5 .

These additional 8 bytes are the ICMP Header

4. Setting the Interface :

    Suppose you have two interfaces : Ethernet and WLAN and you want to ping from a particular interface. You can do it with the 'I' Option

Eg: If you want to ping from WLAN(wlan0) interface


      ping -I wlan0 1920.168.1.5


5.  Setting the TimeOut:

    If we want to our ping command to stop after some time,say 10 seconds, we can do it by using the 'w' option

Eg: If we want to stop the ping after 10 seconds

     ping -w 10 192.168.1.5


6. Checking the Route of Ping Packet:

    If we want to know the route the packets take to reach the other node,we use 'R' command

Eg: ping -R 192.168.1.5


7. ping version:

 In order to check the ping version we can use 'V' option
Eg: ping -V

8. Flooding:

  In order to flood the network with hundreds of packets use 'f' option

Eg: ping -f 192.168.1.5

Comments

Post a Comment

Popular posts from this blog

bb.utils.contains yocto

-
Image
bb.utils.contains  is most commonly used function in Yocto. grep in poky directory returned with 696 count. $ grep -nr 'bb.utils.contains' poky/ | wc -l 696 It's definition is present in 'poky/bitbake/lib/bb/utils.py' file This function returns third argument if the second argument is subset of the first argument else returns fourth argument Let's take an example to understand this. You can see from the above screenshot, when the second argument is a subset of first argument, "present" was returned, else "notpresent" was returned We can also use bb.utils.contains inside if loop. This we can use inside a recipe. if ${@bb.utils.contains('SOMEFLAG','NEWVALUE3','true','false',d)}; then     FOO = 'HELLO' fi
Read more

Difference between RDEPENDS and DEPENDS in Yocto

-
We normally observe these two (RDEPENDS and DEPENDS) whenever we open any recipe. What should we choose when we write our own recipe. DEPENDS -> Build Time Dependency RDEPENDS -> Run Time Dependency DEPENDS: When a recipe 'A' is DEPENDS on recipe 'B'. In this case, Bitbake first builds recipe 'B' and then recipe 'A' E.g. You need 'dbus' to be built before 'wpa_supplicant'. RDEPENDS: When a recipe 'A' is RDEPENDS on recipe 'B'. In this case, Bitbake deploys 'B' on the target system when it deploys 'A'.  E.g. 'perf' RDEPENDS on 'bash' In other words, DEPENDS are those set of packages that should be available while building package, whereas RDEPENDS are set of packages that should be available during execution of the program.
Read more

make config vs oldconfig vs defconfig vs menuconfig vs savedefconfig

-
Image
Building the Linux Kernel is a two-step process: Configuring the Kernel options Building the Kernel with those options. There are many methods available for configuring the kernel. make config: Text-based Configuration.  Options are prompted one after another. All options need to be answered Access to former options is not possible make menuconfig: Menu-driven user interface Allows to navigate forwards and backward directly between features Allows to load and save files with filenames different from ".config" Provides search feature It uses ncurses library for GUI. If the ncurses library is not installed, make menuconfig option fails. To install ncurses library on Ubuntu: sudo apt-get install libncurses5-dev make defconfig: Creates a ".config" file with default options from the ARCH supplied defconfig Configurations are generally stored in the directory: arch/$(ARCH)/configs $ ls arch/x86/configs/ i386_defconfi
Read more