Open | Filtered: No answer is given by the host so the port may be filtered by a firewall. Like in the above image of the UDP Scan Result when the host sends a response like ICMP Unreachable then the port is considered as filtered.Ĥ. If the host sends an Unusual response then also the port is filtered. Filtered: Port is filtered by a security system like Firewall and port is open or closed is not determined. Closed: This means the service is not listening at that port.ģ. One of the popular know usages of NMAP is to find the open ports in the network.NMAP can be installed on Windows, Linux, macOS, and much more. Open: A port is Open means that a service is listening to the port, for example, a MySQL service running at port 3306 as you can see in the TCP Scan result image.Ģ. NMAP (Network Mapper), one of the famous open-source tools to perform network scans, security auditing, and find vulnerabilities in network infrastructure. There are mainly 4 types of State in the port scan results.ġ. you can also use it to check for a single IP to check that the host is up or not.ĭifferent States of the Port Scan Results and their Meaning: The above command does not tell anything about the ports of the system. Only print the available host that responds to the host Discovery probes within the network. Here: -sn and -sP both are used for Ping Scan. It generally sends the empty UDP packets and it takes more time than TCP Scan. Here: -sU is used to activate the UDP Scan.
This scan is done by the privileged users only means for Linux system the Root user and for Windows system Admin. The host keeps any record of the system by which this scan is done. The host Does not keep any record of the system by which this scan is done. Because of the interruption Destination or host does not keep a record of the Source system.ĭifference between SYN Scan and TCP Scan: SYN SCAN TCP SCAN 3-way handshake not completed. In this scan, Source sends the SYN packet and the destination responds with SYN/ACK packets but the source interrupts the 3-way handshake by sending the RST packet. SYN Scan is the same as TCP Scan because it does not complete the 3-way handshake process. SYN Scan/Stealth Scan/Half Open Scan: nmap -sS 192.168.1.12 -top-ports 50 In the above image, you can see the result of the TCP scan you can see the port number and state of the ports and services on these ports.
How to Hack WPA/WPA2 WiFi Using Kali Linux?ģ-way handshake if the Destination port is close.Mutex lock for Linux Thread Synchronization.SORT command in Linux/Unix with examples.AWK command in Unix/Linux with examples.Sed Command in Linux/Unix with examples.ISRO CS Syllabus for Scientist/Engineer Exam.ISRO CS Original Papers and Official Keys.GATE CS Original Papers and Official Keys.