Skip to main content

Secure nginx with Let's Encrypt on Ubuntu 18.04

How to check and open ports in Linux

The most common host-based tool for checking for open ports on Windows or Unix systems is the netstat command.

To see open TCP Network Ports :- 
vishal@vyas:~# netstat -vatn

To see DNS Hostnames :- 
vishal@vyas:~# netstat -vat


To see open UDP Network Ports:- 
vishal@vyas:~# netstat -vaun



===================================================================

Nmap (“Network Mapper”) is an open source tool for network exploration and security auditing. Nmap can provide further information on targets, including reverse DNS names, operating system guesses, device types, and MAC addresses.


vishal@vyas:~# nmap -sS 10.10.10.50

Starting Nmap 4.53 ( http://insecure.org ) at 2011-12-26 12:35 IST
Interesting ports on vishalvyas.com (10.10.10.50):
Not shown: 1703 closed ports
PORT      STATE SERVICE
22/tcp    open  ssh
80/tcp    open  http
110/tcp   open  pop3
111/tcp   open  rpcbind
139/tcp   open  netbios-ssn
143/tcp   open  imap
445/tcp   open  microsoft-ds
993/tcp   open  imaps
995/tcp   open  pop3s
3306/tcp  open  mysql
10000/tcp open  snet-sensor-mgmt

Nmap done: 1 IP address (1 host up) scanned in 0.404 seconds.


general structure of a nmap command is
#nmap <options> <ip address>
Some of important nmap command line options are
-A : which is used for telling Nmap to use advance options of Nmap(like OS finger printing).
-O : For OS finger printing ie finding out Operating system running in the remote host. 

Thanks,
Vishal.

Comments

Popular posts from this blog

Another instance of Certbot is already running - Solved - Linux guru

Error : Another instance of Certbot is already runningcertbot --server https://acme-v02.api.letsencrypt.org/directory --manual --preferred-challenges dns --installer nginx -d *.vishalvyas.com Another instance of Certbot is already running Reason : when you run certbot form your machine and unexpectedly stop the command, Then cert bot is not running but it left some .certbot.lock files behind.You need to kill the certbot instance form your machine. Solution : Run the below command to find killed certbot.find / -type f -name ".certbot.lock" You can see result of the command, If there are, you can remove them. Run below command to remove them.find / -type f -name ".certbot.lock" -exec rm {} \; And try again.

Install Apache Using Ansible Playbooks

Ansible is a automation tool which is widely used, you can install and install, configure and manage number of system and services remotely. you can install software and manage services and tasks without needing manually log in to each servers. you have to install ansible in one machine and use ssh to communicate host each other.



Ansible uses Playbooks which is written in YAML format. it's uses module base format. with playbook can run multiple tasks at time and provide more advance functionality, YAML file always start with "---" syntax. In this article we will see how to install and configure apahce2 using ansible YAML script. Master server : 10.80.253.11 [Ansible server, ] Slave 1 : 10.80.253.12 [need to install apache2 in slave 1] Slave 2 : 10.80.253.13 [need to install apache2 in slave 2] We need to configure slave server info in our ansible configuration file, click here to know how to add client machine to ansible. Let's update our apache2.yml file and install…

Create aws s3 bucket using cli

In this article i will explain you to how to manage s3 bucket and objects using AWS cli command line interface. for that you will have to configure AWS cli interface to your local linux machine. You can configure cli from. HERE.




After configured aws cli to your local machine, you can run all below commands. How to create bucket using AWS Cli.root@master:~# aws s3 mb s3://linuxgurubucket make_bucket: linuxgurubucket Listing Bucket : To list all bucket : root@master:~# aws s3 ls 2018-05-01 15:28:37 linuxgurubucket To list all objects from bucket :root@master:~# aws s3 ls s3://linuxgurubucket 2018-05-01 15:32:16 71515 vishal.jpg How to copy local file to s3 using aws cp command :root@master:~# aws s3 cp ansible.sh s3://linuxgurubucket/ upload: ./ansible.sh to s3://linuxgurubucket/ansible.sh To check it's upload or not :root@master:~# aws s3 ls s3://linuxgurubucket/ 2018-05-01 15:34:19 82 ansible.sh 2018-05-01 15:32:16 71515 vishal.jpg To remove file from s3 bucket using cli: