How to use nmap to check udp port

This nmap example explains how to use nmap to check UDP port (OPEN OR CLOSED )on a system. DNS works on UDP. We initiate UDP scan on a DNS server to check its status. The script is shown below.

nmap -sU -p 53 192.168.1.5

-sU: This option tells Nmap to perform a UDP scan.

-p 53: This option specifies the port number you want to scan. Since it is a DNS server port 53 is initiated.

192.168.1.5: The IP address of the DNS server.

When you run the command, Nmap will send UDP packets to the target system’s UDP port 53.

The status of the ports (open and closed ) are shown below.

nmap check udp port (Closed)

Nmap scan report for 192.168.1.5
Host is up (0.10s latency).

PORT STATE SERVICE
53/udp closed domain
Nmap done: 1 IP address (1 host up) scanned in 1.23 seconds

Nmap scan reports that UDP port 53 is “closed.” This implies that no response was recieved and the port is closed

nmap check udp port (Open)

Nmap scan report for 192.168.1.5
Host is up (0.10s latency).

PORT STATE SERVICE
53/udp open domain

Nmap done: 1 IP address (1 host up) scanned in 1.23 seconds

Nmap scan reports that UDP port 53 is “open.” This implies that a response was recieved and the port is open.

——————————————————————————————————————-
Ebooks & Courses

Nmap tutorials for network administrators

The Nmap tutorials for network administrators is the ultimate nmap cheat sheet which contains nmap commands recommended for day to day network administration activity. The book is ideal for network administrators using nmap for network analysis. The ebook can be purchased from Amazon.

Wireshark tutorials for Network administrators

TheWireshark tutorials for Network administrators is the utlimate wireshark cheat sheet which explains how to use wireshark for network analysis activity. It contains screenshots of wireshark filters and useful techniques which can be used for network administration. The ebook can be purchased from Amazon.

Scapy Python Network Programming Course

The Scapy Python Network Programming Course teaches how to build your own network tools and scripts with Python & Scapy. The course teaches packet crafting framework with scapy and how to integrate Python with scapy to build your own network tools & scripts. The course contains detailed examples of source code with explanation.