Docker Swarm

Docker swarm is a group of machines. Each machine must have Docker installed in it. A command can be executed on the cluster by swarm manager. Swarm managers are the only authorized machines to execute Docker commands on the cluster. In the swarm every machine is known as Node. Other than manager, all nodes are…Read more Docker Swarm

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Building and deploying Docker image

I have already discussed about Docker installation and configuration. Let’s create and deploy Docker application. Why building a Docker Image? Suppose you are developing automation scripts using python, which needs certain environment to be set up. That means your program will not work on other servers if that server does not have same environment. So…Read more Building and deploying Docker image

DOCKER CONTAINER

WHAT IS DOCKER CONTAINER? Linux container image is a stand-alone executable package that includes everything need to run a piece of software, including code, executables, libraries and settings etc and the container is the runtime instance of this image. I won’t repeat about Linux containers again, as I have already discussed earlier about containers and…Read more DOCKER CONTAINER

How to install and use LXC (LinuX Container)

I have already discussed about Linux containers in my previous post. So let’s get started with one of the popular Linux container application “LXC”. Installation is pretty much straight forward. Just do [apt update]                 # to update your ubuntu repositories [apt upgrade]               # to upgrade installed packages [apt…Read more How to install and use LXC (LinuX Container)

How to tune TCP STACK in Linux?

TCP stack has generic default settings which is optimal for almost all kind of networks. But it allows to change its parameters to better suite your particular network configuration. An optimized or properly configured tcp stack can improve network performance upto 10 times and on the other hand, failing to configure properly will degrade the…Read more How to tune TCP STACK in Linux?

TCP Congestion control and avoidance

In real world networking, where differect types of networking devices with different capabilities are present, which may stuck our network. That may be due to end devices limitations, intermidiate devices issues or link issues etc. If a device with transmitting capability of 100mbps, sends traffic with same speed to a receiver which could only receive…Read more TCP Congestion control and avoidance

How to use Linux Bash History / history command?

If you are spending lot of time on Linux command line or maintaining a server, probably you may want to keep track of commands which were executed on your machine and  knowing the history command usage will speed up your work flow. Linux maintains history in ".bash_history" file by default. It maintains different sessions for…Read more How to use Linux Bash History / history command?

TCP STATES/ TCP PROTOCOL OPERATION

The OS is responsible for managing TCP connections, i.e. It creates socket, establishes TCP connection by 3-way handshake, allocates resources for the socket or connection, transfers data if any and finally terminates the connection and releases allocated resources. If TCP stack is not implemented correctly, it may be unable to release the resourses which in…Read more TCP STATES/ TCP PROTOCOL OPERATION

How to analyse TCP headers using Python?

To analyse packets I will use tcpdump or tshark to capture packets, pyshark or xml python module to parse packets. [tcpdump -D] to find all interfaces [tcpdump -i INTERFACE_NAME -w /PATH/To/FILE.pcap tcp] to capture packets Ex: [root@arch tmp]# tcpdump -D | head -4 1.eth0 [Up, Running] 2.any (Pseudo-device that captures on all interfaces) [Up, Running]…Read more How to analyse TCP headers using Python?