On macOS and common Linux distributions such as Ubuntu and Debian, the Netcat package comes pre-installed. Some of the “Netcat” utilities are mentioned below.<\/p>\n
- \n
- Perform Port Scanning through Netcat<\/li>\n
- Sending Files through Netcat<\/li>\n
- Create a web server through Netcat<\/li>\n<\/ul>\n
Syntax:<\/strong><\/p>\n
\n\n
\n \n $ nc [options] host port<\/strong><\/pre>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
Either \u201cnc\u201d or \u201cnetcat\u201d is used on Ubuntu systems.<\/p>\n
A TCP connection will be established to provide host\/hosts and port\/ports by Netcat as\u00a0default. Use the -u option if you want to create a UDP connection.<\/p>\n
\n\n
\n \n $ nc -u host port<\/pre>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
Perform Port Scanning through Netcat<\/strong><\/h4>\n
One of the most prevalent Netcat applications is port scanning. You have the option of scanning a single port or a range of ports.<\/p>\n
TCP:<\/strong><\/p>\n
Scan for open ports:<\/strong><\/h4>\n
To scan the open ports in the range of 30-60 using Netcat, run the command mentioned below:<\/p>\n
\n\n
\n \n $ nc -z -v 10.0.2.15 30-60<\/strong><\/pre>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
![\"Graphical](\"http:\/\/linuxways.net\/wp-content\/uploads\/2022\/02\/graphical-user-interface-text-description-automa-9.png\")
<\/p>\n-z<\/strong> will instruct NC to just scan for open ports and not to send any data to them.<\/p>\n
-v<\/strong> tells the info about verbose.<\/p>\n
Filter the result using the grep command:<\/p>\n
\n\n
\n \n $ nc -z -v 10.0.2.15 2>&1 | grep succeeded<\/strong><\/pre>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
![\"Text](\"http:\/\/linuxways.net\/wp-content\/uploads\/2022\/02\/text-description-automatically-generated-32.png\")
<\/p>\nNo connection was successful in this range.<\/p>\n
UDP:<\/strong><\/p>\n
Simply add the -u parameter to the script to check for UDP ports in the below-mentioned command:<\/p>\n
\n\n
\n \n $ nc -z -v -u 10.0.2.15 30-60<\/strong><\/pre>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
![\"Text](\"http:\/\/linuxways.net\/wp-content\/uploads\/2022\/02\/text-description-automatically-generated-33.png\")
<\/p>\nThere is no UDP port in this range.<\/p>\n
Sending Files through Netcat<\/strong><\/h3>\n
By establishing a basic client or server model, Netcat may be used to transport data from one host to another. This is accomplished using the -l option on the receiving host to set Netcat to listen on a certain port, then creating a standard TCP connection from multiple computers and transferring the file across it.<\/p>\n
Run the below-mentioned command on the receiving end, which opens port 6666 for incoming connections and diverts the output result to the file:<\/p>\n
\n\n
\n \n $ nc -l 6666 > linux1.txt<\/strong><\/pre>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
![\"Graphical](\"http:\/\/linuxways.net\/wp-content\/uploads\/2022\/02\/graphical-user-interface-website-description-aut-2.png\")
<\/p>\nLinux1.txt is the filename to be opened for writing, and you can change the filename according to your requirements.<\/p>\n
Now receiving host will be connected to sending host and sends the file:<\/p>\n
\n\n
\n \n $ nc google.com 6666 < linux2.txt<\/strong><\/pre>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
![\"Graphical](\"http:\/\/linuxways.net\/wp-content\/uploads\/2022\/02\/graphical-user-interface-text-description-automa-10.png\")
<\/p>\nCreating Web Server Through Netcat<\/strong><\/h3>\n
Firstly, create a simple HTML “linux, html” file by using the nano command:<\/p>\n
\n\n
\n \n $ nano linux.html<\/strong><\/pre>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
![\"Text](\"http:\/\/linuxways.net\/wp-content\/uploads\/2022\/02\/text-description-automatically-generated-34.png\")
<\/p>\nType the below mentioned content or you can add content according to your requirement following the html file rules.<\/p>\n
\n\n
\n \n <html><\/strong>\r\n\r\n <head><\/strong>\r\n\r\n <title> Linux<title><\/strong>\r\n\r\n <head><\/strong>\r\n\r\n<html><\/strong><\/pre>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
![\"Graphical](\"http:\/\/linuxways.net\/wp-content\/uploads\/2022\/02\/graphical-user-interface-text-description-automa-11.png\")
<\/p>\nSave by \u201cCtrl+S\u201d and close the file by \u201cCtrl+X\u201d.<\/p>\n
\n\n
\n \n $ printf 'HTTP\/1.1 200 OK\\n\\n%s' \"$(cat linux.html)\" | netcat -l 8888<\/strong><\/pre>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
![\"Text](\"http:\/\/linuxways.net\/wp-content\/uploads\/2022\/02\/text-description-automatically-generated-35.png\")
<\/p>\nNow in the browser, you can access the file by below-mentioned link:<\/p>\n
\n\n
\n \n http:\/\/server-ip:8888<\/strong><\/pre>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
Conclusion:<\/strong><\/h2>\n
Netcat is a basic Linux utility that uses the TCP\/UDP protocols for reading and writing data across network connections. It’s intended to be a dependable backend tool that may be operated directly or simply by other applications and programs. This article gives information about the usage of Netcat with TCP and UDP protocol and some other uses like scanning ports, sending files, and creating a web server.<\/p>","protected":false},"excerpt":{"rendered":"
Reading and writing are the basic operations that can be applied to data in every system. TCP is abbreviated as Transmission Control Protocol and is a connection-oriented communication…<\/p>","protected":false},"author":1,"featured_media":15763,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[921],"class_list":["post-15754","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-ubuntu","tag-netcat-command"],"_links":{"self":[{"href":"https:\/\/linuxways.net\/de\/wp-json\/wp\/v2\/posts\/15754","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/linuxways.net\/de\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/linuxways.net\/de\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/linuxways.net\/de\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/linuxways.net\/de\/wp-json\/wp\/v2\/comments?post=15754"}],"version-history":[{"count":0,"href":"https:\/\/linuxways.net\/de\/wp-json\/wp\/v2\/posts\/15754\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/linuxways.net\/de\/wp-json\/wp\/v2\/media\/15763"}],"wp:attachment":[{"href":"https:\/\/linuxways.net\/de\/wp-json\/wp\/v2\/media?parent=15754"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/linuxways.net\/de\/wp-json\/wp\/v2\/categories?post=15754"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/linuxways.net\/de\/wp-json\/wp\/v2\/tags?post=15754"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}