Nmap stands for “Network Mapper“, is one of the best open-source utility available now for network discovery and security auditing.
Nmap sends packets and analyzes the response it gets to discover hosts and services on a computer network. It is one of the most widely used port scanners available today to help you find open ports and detecting security risks on a network.
This is the first step for an attacker to get information about the network of targets and identify a potential way to launch an attack. An attacker will know about the services running on open ports along with their version, which helps in determining vulnerabilities for the corresponding version.
It is popularly known as System Administrator’s Swiss Army Knife owing its ability to serve multiple purposes – probing computer networks, host discovery, port scan, vulnerability detection, OS detection, version detection, etc. Its cross-platform utility.
If you do not like working in the command-line interface, it is also available in a GUI – Zenmap, the official Nmap Security Scanner GUI.
Installation
We will demonstrate the installation of Nmap on two commonly used Linux distribution – CentOS and Ubuntu. It is available as a package in most Linux distribution’s repository.
Installing Nmap On CentOS 6/7.x
- To install the Nmap package on CentOS, run the command:
sudo yum install nmap$sudo yum install nmap
Loaded plugins: fastestmirror, security
Setting up Install Process
Loading mirror speeds from cached hostfile
* base: mirror.vcu.edu
* centos-sclo-rh: mirror.cc.columbia.edu
* centos-sclo-sclo: mirror.rackspace.com
* epel: reflector.westga.edu
* extras: centos5.zswap.net
* updates: mirror.jaleco.com
Resolving Dependencies
--> Running transaction check
---> Package nmap.x86_64 2:5.51-6.el6 will be installed
--> Finished Dependency Resolution
Dependencies Resolved
======================================================================================================================================================================================================================================================
Package Arch Version Repository Size
======================================================================================================================================================================================================================================================
Installing:
nmap x86_64 2:5.51-6.el6 base 2.8 M
Transaction Summary
======================================================================================================================================================================================================================================================
Install 1 Package(s)
Total download size: 2.8 M
Installed size: 9.7 M
Is this ok [y/N]:- The system will prompt to confirm and complete the installation. Type
yand press Enter
Is this ok [y/N]: y
Downloading Packages:
nmap-5.51-6.el6.x86_64.rpm | 2.8 MB 00:00
Running rpm_check_debug
Running Transaction Test
Transaction Test Succeeded
Running Transaction
Installing : 2:nmap-5.51-6.el6.x86_64 1/1
Verifying : 2:nmap-5.51-6.el6.x86_64 1/1
Installed:
nmap.x86_64 2:5.51-6.el6
Complete!
$- Check if it was installed successfully and the version installed, execute the below command.
$nmap -version
Nmap version 5.51 ( http://nmap.org )Installing Nmap on CentOS 8.x
- We will use DNF to install.
$sudo dnf install nmap -y
Last metadata expiration check: 0:58:54 ago on Fri 18 Sep 2020 07:04:54 PM UTC.
Dependencies resolved.
======================================================================================================================================================================================================================================================
Package Architecture Version Repository Size
======================================================================================================================================================================================================================================================
Installing:
nmap x86_64 2:7.70-5.el8 AppStream 5.8 M
Installing dependencies:
nmap-ncat x86_64 2:7.70-5.el8 AppStream 237 k
Transaction Summary
======================================================================================================================================================================================================================================================
Install 2 Packages
Total download size: 6.1 M
Installed size: 25 M
Downloading Packages:
(1/2): nmap-ncat-7.70-5.el8.x86_64.rpm 669 kB/s | 237 kB 00:00
(2/2): nmap-7.70-5.el8.x86_64.rpm 9.2 MB/s | 5.8 MB 00:00
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Total 8.0 MB/s | 6.1 MB 00:00
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
Preparing : 1/1
Installing : nmap-ncat-2:7.70-5.el8.x86_64 1/2
Running scriptlet: nmap-ncat-2:7.70-5.el8.x86_64 1/2
Installing : nmap-2:7.70-5.el8.x86_64 2/2
Running scriptlet: nmap-2:7.70-5.el8.x86_64 2/2
Verifying : nmap-2:7.70-5.el8.x86_64 1/2
Verifying : nmap-ncat-2:7.70-5.el8.x86_64 2/2
Installed:
nmap-2:7.70-5.el8.x86_64 nmap-ncat-2:7.70-5.el8.x86_64
Complete!
$With -y option, DNF/YUM will install the specified package without asking for confirmation.
DNF(Dandified Yum) is the new package manager in RHEL/CentOS 8 which can be used to install packages. It is the next-generation version of the YUM( Yellowdog Updater Modified) and intended to be a substitution of YUM in RPM-based systems.
- And, to verify the installation.
$nmap -version
Nmap version 7.70 ( https://nmap.org )
Platform: x86_64-redhat-linux-gnu
Compiled with: liblua-5.3.3 openssl-1.1.1 libpcre-8.42 libpcap-1.9.0-PRE-GIT nmap-libdnet-1.12 ipv6
Compiled without: libssh2 libz
Available nsock engines: epoll poll selectUbuntu
- Run the below command to make sure all packages are up-to-date on the Ubuntu server.
sudo apt-get update- Execute the below command to install
$sudo apt-get install nmap -y
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following package was automatically installed and is no longer required:
libnuma1
Use 'sudo apt autoremove' to remove it.
The following additional packages will be installed:
libblas3 liblinear4 liblua5.3-0 lua-lpeg nmap-common
Suggested packages:
liblinear-tools liblinear-dev ncat ndiff zenmap
The following NEW packages will be installed:
libblas3 liblinear4 liblua5.3-0 lua-lpeg nmap nmap-common
0 upgraded, 6 newly installed, 0 to remove and 30 not upgraded.
Need to get 5669 kB of archives.
After this operation, 26.8 MB of additional disk space will be used.
Get:1 http://us-west1.gce.archive.ubuntu.com/ubuntu focal/main amd64 libblas3 amd64 3.9.0-1build1 [142 kB]
Get:2 http://us-west1.gce.archive.ubuntu.com/ubuntu focal/universe amd64 liblinear4 amd64 2.3.0+dfsg-3build1 [41.7 kB]
Get:3 http://us-west1.gce.archive.ubuntu.com/ubuntu focal/main amd64 liblua5.3-0 amd64 5.3.3-1.1ubuntu2 [116 kB]
Get:4 http://us-west1.gce.archive.ubuntu.com/ubuntu focal/universe amd64 lua-lpeg amd64 1.0.2-1 [31.4 kB]
Get:5 http://us-west1.gce.archive.ubuntu.com/ubuntu focal/universe amd64 nmap-common all 7.80+dfsg1-2build1 [3676 kB]
Get:6 http://us-west1.gce.archive.ubuntu.com/ubuntu focal/universe amd64 nmap amd64 7.80+dfsg1-2build1 [1662 kB]
Fetched 5669 kB in 1s (7683 kB/s)
Selecting previously unselected package libblas3:amd64.
(Reading database ... 62831 files and directories currently installed.)
Preparing to unpack .../0-libblas3_3.9.0-1build1_amd64.deb ...
Unpacking libblas3:amd64 (3.9.0-1build1) ...
Selecting previously unselected package liblinear4:amd64.
Preparing to unpack .../1-liblinear4_2.3.0+dfsg-3build1_amd64.deb ...
Unpacking liblinear4:amd64 (2.3.0+dfsg-3build1) ...
Selecting previously unselected package liblua5.3-0:amd64.
Preparing to unpack .../2-liblua5.3-0_5.3.3-1.1ubuntu2_amd64.deb ...
Unpacking liblua5.3-0:amd64 (5.3.3-1.1ubuntu2) ...
Selecting previously unselected package lua-lpeg:amd64.
Preparing to unpack .../3-lua-lpeg_1.0.2-1_amd64.deb ...
Unpacking lua-lpeg:amd64 (1.0.2-1) ...
Selecting previously unselected package nmap-common.
Preparing to unpack .../4-nmap-common_7.80+dfsg1-2build1_all.deb ...
Unpacking nmap-common (7.80+dfsg1-2build1) ...
Selecting previously unselected package nmap.
Preparing to unpack .../5-nmap_7.80+dfsg1-2build1_amd64.deb ...
Unpacking nmap (7.80+dfsg1-2build1) ...
Setting up lua-lpeg:amd64 (1.0.2-1) ...
Setting up libblas3:amd64 (3.9.0-1build1) ...
update-alternatives: using /usr/lib/x86_64-linux-gnu/blas/libblas.so.3 to provide /usr/lib/x86_64-linux-gnu/libblas.so.3 (libblas.so.3-x86_64-linux-gnu) in auto mode
Setting up nmap-common (7.80+dfsg1-2build1) ...
Setting up liblua5.3-0:amd64 (5.3.3-1.1ubuntu2) ...
Setting up liblinear4:amd64 (2.3.0+dfsg-3build1) ...
Setting up nmap (7.80+dfsg1-2build1) ...
Processing triggers for man-db (2.9.1-1) ...
Processing triggers for libc-bin (2.31-0ubuntu9) ...- And, run the
-versionto ensure it is installed.
$nmap -version
Nmap version 7.80 ( https://nmap.org )
Platform: x86_64-pc-linux-gnu
Compiled with: liblua-5.3.3 openssl-1.1.1d nmap-libssh2-1.8.2 libz-1.2.11 libpcre-8.39 libpcap-1.9.1 nmap-libdnet-1.12 ipv6
Compiled without:
Available nsock engines: epoll poll selectReal-time Nmap Usage Example
We will see a few examples illustrating the usage of the Nmap command.
Scan for open ports
Syntax for nmap
nmap [Scan Type(s)] [Options] {target specification}
Target specification could be a hostname, IP address, domain name, network, subnet, etc.
Scan a domain
nmap scanme.nmap.org$nmap scanme.nmap.org
Starting Nmap 7.80 ( https://nmap.org ) at 2020-09-18 20:14 UTC
Nmap scan report for scanme.nmap.org (45.33.32.156)
Host is up (0.025s latency).
Other addresses for scanme.nmap.org (not scanned): 2600:3c01::f03c:91ff:fe18:bb2f
Not shown: 995 closed ports
PORT STATE SERVICE
22/tcp open ssh
25/tcp filtered smtp
80/tcp open http
9929/tcp open nping-echo
31337/tcp open Elite
Nmap done: 1 IP address (1 host up) scanned in 1.73 secondsWith no flags, Nmap will, by default –
- Scan for the top 1000 commonly used ports (list of these ports can be modified in the nmap-services file).
- Nmap with attempt a TCP SYN connection to ports when running with a privileged user.
- Sends ICMP echo requests to target hosts to confirm if it is alive or not.
- Will perform a DNS reverse lookup to get the hostname.
We could see four open ports, one filtered port, and 995 closed ports in the output shown above. A port that cannot be determined by Nmap if it is closed or open, which may be due to a firewall, is filtered.
Here in the example shown above, we scan scanme.nmap.com, which has authorized itself to be scanned.
nmap -F scanme.nmap.orgYou could also use the fast scan option -F to scan only the top 100 most commonly used ports of each protocol it is asked to scan.
Scan IP address
nmap 192.168.0.7$nmap 192.168.0.7
Starting Nmap 7.80 ( https://nmap.org ) at 2020-09-18 20:12 UTC
Nmap scan report for server-1.geekflare.com (192.168.0.7)
Host is up (0.034s latency).
Not shown: 999 closed ports
PORT STATE SERVICE
22/tcp open ssh
Nmap done: 1 IP address (1 host up) scanned in 0.62 secondsScan a subnet
nmap 192.168.0.0/24$nmap 192.168.0.0/24
Starting Nmap 7.80 ( https://nmap.org ) at 2020-09-18 20:15 UTC
Nmap scan report for server-1.geekflare.com (192.168.0.7)
Host is up (0.044s latency).
Not shown: 999 closed ports
PORT STATE SERVICE
22/tcp open ssh
Nmap scan report for server-2.geekflare.com (192.168.0.8)
Host is up (0.046s latency).
Not shown: 999 closed ports
PORT STATE SERVICE
22/tcp open ssh
Nmap scan report for server-3.geekflare.com (192.168.0.9)
Host is up (0.043s latency).
Not shown: 999 closed ports
PORT STATE SERVICE
22/tcp open ssh
Nmap scan report for server-4.geekflare.com (192.168.0.10)
Host is up (0.044s latency).
Not shown: 999 closed ports
PORT STATE SERVICE
22/tcp open ssh
Nmap done: 256 IP addresses (4 hosts up) scanned in 4.67 secondsScanning multiple hosts
Scanning multiple hosts is easy!
- Add hostnames or IP addresses you want to scan one after another in a row
nmap 192.168.0.1 192.168.0.3 192.168.0.4- Use comma
Above mentioned command could also be written as below to avoid mentioning the IP address again
nmap 192.168.0.1,3,4- Use hyphens (-) to specify the IP address range as shown below
nmap 192.168.0.1-20The above command will scan the first twenty hosts of the sub-network.
- Use wild cards to scan entire subnet –
nmap 192.168.0.*The above command will scan for all 256 IP addresses in the subnet.
- Read Hosts from a file
You could specify all the hosts required to be scanned in a file and use the command below –
nmap -iL /tmp/hostfileExample of host file –
cat /tmp/hostfile
192.168.0.1,2,4
scanme.nmap.org
10.0.0-255.1-254- Exclude hosts from search
You could exclude a few hosts from a group search if you want.
nmap 192.168.0.* --exclude 192.168.0.2
nmap 192.168.0.1-40 --exclude 192.168.0.5,6,7You could also exclude hosts from your search using the –excludefile flag
nmap 192.168.0.* --excludefile /tmp/hosts.txtNmap Port Selection
To scan specific ports on a system, instead of the default top 1000 commonly used ports, you could use -p parameter.
nmap -p 22,80,443 192.168.0.2-50$nmap -p 22,80,443 192.168.0.2-50
Starting Nmap 7.70 ( https://nmap.org ) at 2020-09-18 20:18 UTC
Nmap scan report for server-1.geekflare.com (192.168.0.7)
Host is up (0.00018s latency).
PORT STATE SERVICE
22/tcp open ssh
80/tcp closed http
443/tcp closed https
Nmap scan report for server-2.geekflare.com (192.168.0.8)
Host is up (0.00094s latency).
PORT STATE SERVICE
22/tcp open ssh
80/tcp closed http
443/tcp closed https
Nmap scan report for server-3.geekflare.com (192.168.0.9)
Host is up (0.00092s latency).
PORT STATE SERVICE
22/tcp open ssh
80/tcp closed http
443/tcp closed https
Nmap scan report for server-4.geekflare.com (192.168.0.10)
Host is up (0.00089s latency).
PORT STATE SERVICE
22/tcp open ssh
80/tcp closed http
443/tcp closed https
Nmap done: 49 IP addresses (4 hosts up) scanned in 1.65 secondsThe above command will scan only for ports 22, 80, and 443 on the IP addresses mentioned.
nmap -p 1-500 192.168.0.2The above command will scan for ports 1 to 500 on the host mentioned.
nmap -p- 192.168.0.2Using -p- will scan all 65535 ports.
Redirecting output to a file
By default, Nmap prints the output on the terminal, but when scanning a large network, it is better to save the results in a file for better analysis. You can save the results of its scans in different file formats.
Normal output format [-oN]
Normal mode will give you the output as you see it on your screen.
nmap -oN /tmp/scanResult.txt 192.168.0.0/24XML output format [-oX]
We could export the results in XML format. It is one of the most used file formats as most programming languages have libraries for XML parsing.
nmap -oX /tmp/scanResult.xml 192.168.0.0/24Grepable Output format [-oG]
We get the output in a format that is very easily used with the grep command. The output could later be fed to command-line utilities like – awk, grep, sed to perform additional operations as required.
nmap -oG /tmp/scanResult.txt 192.168.0.0/24Script kiddie output [-oS]
It uses the “leet”, replacing letters with their visually alike number representations. This output format is not useful for any particular case and was included only as a joke.
nmap -oS /tmp/scanResult scanme.nmap.org$nmap -oS /tmp/scanResult scanme.nmap.org
Starting Nmap 7.70 ( https://nmap.org ) at 2020-09-18 20:34 UTC
Nmap scan report for scanme.nmap.org (45.33.32.156)
Host is up (0.053s latency).
Other addresses for scanme.nmap.org (not scanned): 2600:3c01::f03c:91ff:fe18:bb2f
Not shown: 995 closed ports
PORT STATE SERVICE
22/tcp open ssh
25/tcp filtered smtp
80/tcp open http
9929/tcp open nping-echo
31337/tcp open Elite
Nmap done: 1 IP address (1 host up) scanned in 2.12 seconds
$
$cat /tmp/scanResult
$tart|Ng Nmap 7.70 ( httpz://NmAp.oRg ) aT 2020-09-18 20:34 UTc
Nmap $can rEp0rt f0r Scanm3.nmap.0rg (45.33.32.156)
H0st iS up (0.053s lat3ncy).
Other addreSSes for $canm3.nmap.0Rg (n0t scanN3D): 2600:3c01::f03c:91ff:fE18:bb2f
Not sh0wn: 995 clOs3d p0rtS
P0rT $TAT3 S3RV|C3
22/TCp op3n Ssh
25/tcp f1ltEr3d $mtp
80/tCp op3n http
9929/tcp Open Nping-ech0
31337/tCP 0pen 3litE
Nmap d0n3: 1 Ip addRe$s (1 hO$t up) $CANN3d In 2.12 s3C0nDzVarious Nmap scan types
TCP Connect Scan [-sT]
This is the basic form of TCP scanning and involves no stealth. It attempts to establish a complete connection with the range ports specified with a complete three-way handshake exchange (SYN -> SYN/ACK -> ACK). A successful connection indicates an open port.
This is the default scan type Nmap uses when executed by an unprivileged user.
nmap -sT 192.168.0.1$nmap -sT 192.168.0.7
Starting Nmap 7.70 ( https://nmap.org ) at 2020-09-18 19:52 UTC
Nmap scan report for server-1.geekflare.com (192.168.0.7)
Host is up (0.00042s latency).
Not shown: 999 closed ports
PORT STATE SERVICE
22/tcp open ssh
Nmap done: 1 IP address (1 host up) scanned in 0.09 secondsTCP SYN Scan [-sS]
Also known as a half-open scan, it is stealthier than TCP connect scan as it never establishes a complete connection. TCP SYN scan is the default scan type when executed as a privileged user, and unprivileged users will not have the permission to run this scan as it requires privileges to raw socket / raw packet.
nmap -sS 192.168.0.1$sudo nmap -sS 192.168.0.7
Starting Nmap 7.70 ( https://nmap.org ) at 2020-09-18 19:51 UTC
Nmap scan report for server-1.geekflare.com (192.168.0.7)
Host is up (0.00022s latency).
Not shown: 999 closed ports
PORT STATE SERVICE
22/tcp open ssh
Nmap done: 1 IP address (1 host up) scanned in 1.50 seconds$nmap -sS 192.168.0.1
You requested a scan type which requires root privileges.
QUITTING!As we could see in the example above, an SYN scan could not be executed with non-privileged users.
UDP scan [-sU]
If no flag is specified, by default, Nmap scans for TCP ports. To scan for UDP port we have to use the -sU flag, as shown below.
$sudo nmap -sU 192.168.0.8
Starting Nmap 7.70 ( https://nmap.org ) at 2020-09-18 19:44 UTC
Nmap scan report for server-2.geekflare.com (192.168.0.8)
Host is up (0.00036s latency).
Not shown: 999 closed ports
PORT STATE SERVICE
5355/udp open|filtered llmnr
Nmap done: 1 IP address (1 host up) scanned in 999.27 secondsPing Scan [-sn]
This is highly useful when you only need to know whether the host is alive or not and do not need information about open ports on the hosts.
This is often referred to as ‘Ping sweep’. In previously released versions of Nmap, -sn was known as -sP.
nmap -sn 192.168.1.0/24$nmap -sn 192.168.1.0/24
Starting Nmap 7.70 ( https://nmap.org ) at 2020-09-18 19:39 UTC
Nmap scan report for server-7.geekflare.com (192.168.1.2)
Host is up (0.033s latency).
Nmap scan report for server-10.geekflare.com (192.168.1.3)
Host is up (0.035s latency).
Nmap scan report for server-13.geekflare.com (192.168.1.4)
Host is up (0.10s latency).
Nmap done: 256 IP addresses (3 hosts up) scanned in 9.85 secondsIn the above example, we could see, in the specified target subnet, out of 256 IP addresses scanned, only three hosts are up.
nmap -sn -n -v 192.168.0.0/24 -oG - | grep -iv down-sn –> Ping scan.
-n –> Ignore the DNS resolution and speed up the scan.
-v –> Add verbose to get more information of scan.
-oG –> Provides the output in grepable format.
- –> Hyphen redirects the grepable output to standard output, which is then piped to grep.
-iv –> Ignore the lines having the word ‘down’.
$nmap -sn -n -v 192.168.0.0/24 -oG - | grep -iv down
# Nmap 7.70 scan initiated Fri Sep 18 19:40:17 2020 as: nmap -sn -n -v -oG - 192.168.0.0/24
# Ports scanned: TCP(0;) UDP(0;) SCTP(0;) PROTOCOLS(0;)
Host: 192.168.0.7 () Status: Up
Host: 192.168.0.8 () Status: Up
Host: 192.168.0.9 () Status: Up
Host: 192.168.0.10 () Status: Up
# Nmap done at Fri Sep 18 19:40:20 2020 -- 256 IP addresses (4 hosts up) scanned in 2.91 secondsWe could see only four hosts are alive out of 256 IP addresses scanned in the subnet.
OS and Service Version Detection
OS Scanning
In addition to port scanning and host discovery, Nmap could also provide information about the underlying operating system. Nmap has one of the largest operating system fingerprint databases and can identify operating systems by analyzing their response to TCP/IP probes.
It could be enabled with the -O flag. Below is the command –
nmap -O localhost$sudo nmap -O localhost
Starting Nmap 7.70 ( https://nmap.org ) at 2020-09-18 19:32 UTC
Nmap scan report for localhost (127.0.0.1)
Host is up (0.000012s latency).
Other addresses for localhost (not scanned): ::1
Not shown: 999 closed ports
PORT STATE SERVICE
22/tcp open ssh
Device type: general purpose
Running: Linux 3.X
OS CPE: cpe:/o:linux:linux_kernel:3
OS details: Linux 3.7 - 3.10
Network Distance: 0 hops
OS detection performed. Please report any incorrect results at https://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 3.89 secondsVersion Scanning
Nmap also helps scanning services running and their version information from open ports. This is helpful in scanning services running on vulnerable versions and could be updated to mitigate the risk.
It could be enabled with -sV
nmap -sV localhost$sudo nmap -sV localhost
Starting Nmap 7.70 ( https://nmap.org ) at 2020-09-18 19:35 UTC
Nmap scan report for localhost (127.0.0.1)
Host is up (0.000010s latency).
Other addresses for localhost (not scanned): ::1
Not shown: 999 closed ports
PORT STATE SERVICE VERSION
22/tcp open ssh OpenSSH 8.0 (protocol 2.0)
Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 1.96 secondsAggressive Scan
Nmap performs an aggressive and advanced scan as well that enables OS detection -O, script scanning -sC, version scanning -sV, and traceroute --traceroute.
We could pass -A argument to perform an aggressive scan.
$sudo nmap -A scanme.nmap.org
Starting Nmap 7.70 ( https://nmap.org ) at 2020-09-18 20:26 UTC
Nmap scan report for scanme.nmap.org (45.33.32.156)
Host is up (0.051s latency).
Other addresses for scanme.nmap.org (not scanned): 2600:3c01::f03c:91ff:fe18:bb2f
Not shown: 995 closed ports
PORT STATE SERVICE VERSION
22/tcp open ssh OpenSSH 6.6.1p1 Ubuntu 2ubuntu2.13 (Ubuntu Linux; protocol 2.0)
| ssh-hostkey:
| 1024 ac:00:a0:1a:82:ff:cc:55:99:dc:67:2b:34:97:6b:75 (DSA)
| 2048 20:3d:2d:44:62:2a:b0:5a:9d:b5:b3:05:14:c2:a6:b2 (RSA)
| 256 96:02:bb:5e:57:54:1c:4e:45:2f:56:4c:4a:24:b2:57 (ECDSA)
|_ 256 33:fa:91:0f:e0:e1:7b:1f:6d:05:a2:b0:f1:54:41:56 (ED25519)
25/tcp filtered smtp
80/tcp open http Apache httpd 2.4.7 ((Ubuntu))
|_http-server-header: Apache/2.4.7 (Ubuntu)
|_http-title: Go ahead and ScanMe!
9929/tcp open nping-echo Nping echo
31337/tcp open tcpwrapped
Aggressive OS guesses: Linux 2.6.32 (94%), Linux 3.2 - 4.9 (94%), Linux 2.6.32 - 3.10 (94%), Linux 3.4 - 3.10 (93%), Linux 3.1 (92%), Linux 3.2 (92%), Linux 3.3 (92%), Synology DiskStation Manager 5.2-5644 (92%), Netgear RAIDiator 4.2.28 (92%), AXIS 210A or 211 Network Camera (Linux 2.6.17) (92%)
No exact OS matches for host (test conditions non-ideal).
Network Distance: 7 hops
Service Info: OS: Linux; CPE: cpe:/o:linux:linux_kernel
TRACEROUTE (using port 143/tcp)
HOP RTT ADDRESS
1 48.15 ms 72.14.239.197
2 52.74 ms 209.85.253.9
3 49.54 ms 142.250.234.59
4 49.99 ms 108.170.242.251
5 50.70 ms 213.52.131.176
6 50.85 ms 173.230.159.71
7 53.40 ms scanme.nmap.org (45.33.32.156)
OS and Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 259.05 seconds
$$sudo nmap -A scanme.nmap.org
Starting Nmap 7.70 ( https://nmap.org ) at 2020-09-18 20:33 UTC
Stats: 0:00:00 elapsed; 0 hosts completed (0 up), 0 undergoing Script Pre-Scan
NSE Timing: About 0.00% doneLegal issues with port scanning
It is always advisable to get written authorization/permission from the owner of the target network before initializing any scan.
For example – http://scanme.nmap.org/ has authorized itself to be scanned. You could read in detail on the official website.
What’s next?
Check out how to install Nmap on Windows.