Vic020的WC 29 Practical Examples of Nmap Commands for Linux System/Network Administrators ================================================================================ The **Nmap** aka **Network Mapper** is an open source and a very versatile tool for Linux system/network administrators. **Nmap** is used for **exploring networks, perform security scans, network audit** and **finding open ports** on remote machine. It scans for Live hosts, Operating systems, packet filters and open ports running on remote hosts. ![Nmap Commands](http://www.tecmint.com/wp-content/uploads/2013/12/Nmap-Commands.png) *Nmap Commands and Examples* I’ll be covering most of **NMAP** usage in two different parts and this is the first part of nmap serious. Here in this setup, I have used two servers without firewall to test the working of the Nmap command. - 192.168.0.100 – server1.tecmint.com - 192.168.0.101 – server2.tecmint.com ### Nmap command usage ### # nmap [Scan Type(s)] [Options] {target specification} ### How to Install NMAP in Linux ### Most of the today’s Linux distributions like **Red Hat, CentOS, Fedoro, Debian** and **Ubuntu** have included **Nmap** in their default package management repositories called [Yum][1] and [APT][2]. The both tools are used to install and manage software packages and updates. To install **Nmap** on distribution specific use the following command. # yum install nmap [on Red Hat based systems] $ sudo apt-get install nmap [on Debian based systems] Once you’ve install latest nmap application, you can follow the example instructions provided in this article. ### 1. Scan a System with Hostname and IP Address ### The **Nmap** tool offers various methods to scan a system. In this example, I am performing a scan using hostname as **server2.tecmint.com** to find out all open ports, services and MAC address on the system. #### Scan using Hostname #### [root@server1 ~]# nmap server2.tecmint.com Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 15:42 EST Interesting ports on server2.tecmint.com (192.168.0.101): Not shown: 1674 closed ports PORT STATE SERVICE 22/tcp open ssh 80/tcp open http 111/tcp open rpcbind 957/tcp open unknown 3306/tcp open mysql 8888/tcp open sun-answerbook MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems) Nmap finished: 1 IP address (1 host up) scanned in 0.415 seconds You have new mail in /var/spool/mail/root #### Scan using IP Address #### [root@server1 ~]# nmap 192.168.0.101 Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-18 11:04 EST Interesting ports on server2.tecmint.com (192.168.0.101): Not shown: 1674 closed ports PORT STATE SERVICE 22/tcp open ssh 80/tcp open http 111/tcp open rpcbind 958/tcp open unknown 3306/tcp open mysql 8888/tcp open sun-answerbook MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems) Nmap finished: 1 IP address (1 host up) scanned in 0.465 seconds You have new mail in /var/spool/mail/root ### 2. Scan using “-v” option ### You can see that the below command with “**-v**” option is giving more detailed information about the remote machine. [root@server1 ~]# nmap -v server2.tecmint.com Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 15:43 EST Initiating ARP Ping Scan against 192.168.0.101 [1 port] at 15:43 The ARP Ping Scan took 0.01s to scan 1 total hosts. Initiating SYN Stealth Scan against server2.tecmint.com (192.168.0.101) [1680 ports] at 15:43 Discovered open port 22/tcp on 192.168.0.101 Discovered open port 80/tcp on 192.168.0.101 Discovered open port 8888/tcp on 192.168.0.101 Discovered open port 111/tcp on 192.168.0.101 Discovered open port 3306/tcp on 192.168.0.101 Discovered open port 957/tcp on 192.168.0.101 The SYN Stealth Scan took 0.30s to scan 1680 total ports. Host server2.tecmint.com (192.168.0.101) appears to be up ... good. Interesting ports on server2.tecmint.com (192.168.0.101): Not shown: 1674 closed ports PORT STATE SERVICE 22/tcp open ssh 80/tcp open http 111/tcp open rpcbind 957/tcp open unknown 3306/tcp open mysql 8888/tcp open sun-answerbook MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems) Nmap finished: 1 IP address (1 host up) scanned in 0.485 seconds Raw packets sent: 1681 (73.962KB) | Rcvd: 1681 (77.322KB) #### Scan Multiple Hosts #### You can scan multiple hosts by simply writing their IP addresses or hostnames with Nmap. [root@server1 ~]# nmap 192.168.0.101 192.168.0.102 192.168.0.103 Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 16:06 EST Interesting ports on server2.tecmint.com (192.168.0.101): Not shown: 1674 closed ports PORT STATE SERVICE 22/tcp open ssh 80/tcp open http 111/tcp open rpcbind 957/tcp open unknown 3306/tcp open mysql 8888/tcp open sun-answerbook MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems) Nmap finished: 3 IP addresses (1 host up) scanned in 0.580 seconds ### 4. Scan a whole Subnet ### You can scan a whole subnet or IP range with Nmap by providing *** wildcard** with it. [root@server1 ~]# nmap 192.168.0.* Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 16:11 EST Interesting ports on server1.tecmint.com (192.168.0.100): Not shown: 1677 closed ports PORT STATE SERVICE 22/tcp open ssh 111/tcp open rpcbind 851/tcp open unknown Interesting ports on server2.tecmint.com (192.168.0.101): Not shown: 1674 closed ports PORT STATE SERVICE 22/tcp open ssh 80/tcp open http 111/tcp open rpcbind 957/tcp open unknown 3306/tcp open mysql 8888/tcp open sun-answerbook MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems) Nmap finished: 256 IP addresses (2 hosts up) scanned in 5.550 seconds You have new mail in /var/spool/mail/root On above output you can see that nmap scanned a whole subnet and gave the information about those hosts which are **Up** in the **Network**. ### 5. Scan Multiple Servers using last octet of IP address ### You can perform scans on multiple IP address by simple specifying last octet of IP address. For example, here I performing a scan on IP addresses 192.168.0.101, 192.168.0.102 and 192.168.0.103. [root@server1 ~]# nmap 192.168.0.101,102,103 Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 16:09 EST Interesting ports on server2.tecmint.com (192.168.0.101): Not shown: 1674 closed ports PORT STATE SERVICE 22/tcp open ssh 80/tcp open http 111/tcp open rpcbind 957/tcp open unknown 3306/tcp open mysql 8888/tcp open sun-answerbook MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems) Nmap finished: 3 IP addresses (1 host up) scanned in 0.552 seconds You have new mail in /var/spool/mail/root ### 6. Scan list of Hosts from a File ### If you have more hosts to scan and all host details are written in a file , you can directly ask nmap to read that file and perform scans. Let’s see how to do that. Create a text file called “**nmaptest.txt**” and define all the IP addresses or hostname of the server that you want to do a scan. [root@server1 ~]# cat > nmaptest.txt localhost server2.tecmint.com 192.168.0.101 Next, run the following command with “**iL**” option with nmap command to scan all listed IP address in the file. [root@server1 ~]# nmap -iL nmaptest.txt Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-18 10:58 EST Interesting ports on localhost.localdomain (127.0.0.1): Not shown: 1675 closed ports PORT STATE SERVICE 22/tcp open ssh 25/tcp open smtp 111/tcp open rpcbind 631/tcp open ipp 857/tcp open unknown Interesting ports on server2.tecmint.com (192.168.0.101): Not shown: 1674 closed ports PORT STATE SERVICE 22/tcp open ssh 80/tcp open http 111/tcp open rpcbind 958/tcp open unknown 3306/tcp open mysql 8888/tcp open sun-answerbook MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems) Interesting ports on server2.tecmint.com (192.168.0.101): Not shown: 1674 closed ports PORT STATE SERVICE 22/tcp open ssh 80/tcp open http 111/tcp open rpcbind 958/tcp open unknown 3306/tcp open mysql 8888/tcp open sun-answerbook MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems) Nmap finished: 3 IP addresses (3 hosts up) scanned in 2.047 seconds ### 7. Scan an IP Address Range ### You can specify an IP range while performing scan with Nmap. [root@server1 ~]# nmap 192.168.0.101-110 Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 16:09 EST Interesting ports on server2.tecmint.com (192.168.0.101): Not shown: 1674 closed ports PORT STATE SERVICE 22/tcp open ssh 80/tcp open http 111/tcp open rpcbind 957/tcp open unknown 3306/tcp open mysql 8888/tcp open sun-answerbook MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems) Nmap finished: 10 IP addresses (1 host up) scanned in 0.542 seconds ### 8. Scan Network Excluding Remote Hosts ### You can exclude some hosts while performing a full network scan or when you are scanning with wildcards with “**–exclude**” option. [root@server1 ~]# nmap 192.168.0.* --exclude 192.168.0.100 Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 16:16 EST Interesting ports on server2.tecmint.com (192.168.0.101): Not shown: 1674 closed ports PORT STATE SERVICE 22/tcp open ssh 80/tcp open http 111/tcp open rpcbind 957/tcp open unknown 3306/tcp open mysql 8888/tcp open sun-answerbook MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems) Nmap finished: 255 IP addresses (1 host up) scanned in 5.313 seconds You have new mail in /var/spool/mail/root ### 9. Scan OS information and Traceroute ### With Nmap, you can detect which OS and version is running on the remote host. To enable OS & version detection, script scanning and traceroute, we can use “**-A**” option with NMAP. [root@server1 ~]# nmap -A 192.168.0.101 Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 16:25 EST Interesting ports on server2.tecmint.com (192.168.0.101): Not shown: 1674 closed ports PORT STATE SERVICE VERSION 22/tcp open ssh OpenSSH 4.3 (protocol 2.0) 80/tcp open http Apache httpd 2.2.3 ((CentOS)) 111/tcp open rpcbind 2 (rpc #100000) 957/tcp open status 1 (rpc #100024) 3306/tcp open mysql MySQL (unauthorized) 8888/tcp open http lighttpd 1.4.32 MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems) No exact OS matches for host (If you know what OS is running on it, see http://www.insecure.org/cgi-bin/nmap-submit.cgi). TCP/IP fingerprint: SInfo(V=4.11%P=i686-redhat-linux-gnu%D=11/11%Tm=52814B66%O=22%C=1%M=080027) TSeq(Class=TR%IPID=Z%TS=1000HZ) T1(Resp=Y%DF=Y%W=16A0%ACK=S++%Flags=AS%Ops=MNNTNW) T2(Resp=N) T3(Resp=Y%DF=Y%W=16A0%ACK=S++%Flags=AS%Ops=MNNTNW) T4(Resp=Y%DF=Y%W=0%ACK=O%Flags=R%Ops=) T5(Resp=Y%DF=Y%W=0%ACK=S++%Flags=AR%Ops=) T6(Resp=Y%DF=Y%W=0%ACK=O%Flags=R%Ops=) T7(Resp=Y%DF=Y%W=0%ACK=S++%Flags=AR%Ops=) PU(Resp=Y%DF=N%TOS=C0%IPLEN=164%RIPTL=148%RID=E%RIPCK=E%UCK=E%ULEN=134%DAT=E) Uptime 0.169 days (since Mon Nov 11 12:22:15 2013) Nmap finished: 1 IP address (1 host up) scanned in 22.271 seconds You have new mail in /var/spool/mail/root In above Output, you can see that nmap is came up with TCP/IP fingerprint of the OS running on remote hosts and being more specific about the port and services running on the remote hosts. ### 10. Enable OS Detection with Nmap ### Use the option “-O” and “-osscan-guess” also helps to discover OS information. [root@server1 ~]# nmap -O server2.tecmint.com Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 17:40 EST Interesting ports on server2.tecmint.com (192.168.0.101): Not shown: 1674 closed ports PORT STATE SERVICE 22/tcp open ssh 80/tcp open http 111/tcp open rpcbind 957/tcp open unknown 3306/tcp open mysql 8888/tcp open sun-answerbook MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems) No exact OS matches for host (If you know what OS is running on it, see http://www.insecure.org/cgi-bin/nmap-submit.cgi). TCP/IP fingerprint: SInfo(V=4.11%P=i686-redhat-linux-gnu%D=11/11%Tm=52815CF4%O=22%C=1%M=080027) TSeq(Class=TR%IPID=Z%TS=1000HZ) T1(Resp=Y%DF=Y%W=16A0%ACK=S++%Flags=AS%Ops=MNNTNW) T2(Resp=N) T3(Resp=Y%DF=Y%W=16A0%ACK=S++%Flags=AS%Ops=MNNTNW) T4(Resp=Y%DF=Y%W=0%ACK=O%Flags=Option -O and -osscan-guess also helps to discover OSR%Ops=) T5(Resp=Y%DF=Y%W=0%ACK=S++%Flags=AR%Ops=) T6(Resp=Y%DF=Y%W=0%ACK=O%Flags=R%Ops=) T7(Resp=Y%DF=Y%W=0%ACK=S++%Flags=AR%Ops=) PU(Resp=Y%DF=N%TOS=C0%IPLEN=164%RIPTL=148%RID=E%RIPCK=E%UCK=E%ULEN=134%DAT=E) Uptime 0.221 days (since Mon Nov 11 12:22:16 2013) Nmap finished: 1 IP address (1 host up) scanned in 11.064 seconds You have new mail in /var/spool/mail/root ### 11. Scan a Host to Detect Firewall ### The below command will perform a scan on a remote host to detect if any packet filters or Firewall is used by host. [root@server1 ~]# nmap -sA 192.168.0.101 Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 16:27 EST All 1680 scanned ports on server2.tecmint.com (192.168.0.101) are UNfiltered MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems) Nmap finished: 1 IP address (1 host up) scanned in 0.382 seconds You have new mail in /var/spool/mail/root ### 12. Scan a Host to check its protected by Firewall ### To scan a host if it is protected by any packet filtering software or Firewalls. [root@server1 ~]# nmap -PN 192.168.0.101 Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 16:30 EST Interesting ports on server2.tecmint.com (192.168.0.101): Not shown: 1674 closed ports PORT STATE SERVICE 22/tcp open ssh 80/tcp open http 111/tcp open rpcbind 957/tcp open unknown 3306/tcp open mysql 8888/tcp open sun-answerbook MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems) Nmap finished: 1 IP address (1 host up) scanned in 0.399 seconds ### 13. Find out Live hosts in a Network ### With the help of “**-sP**” option we can simply check which hosts are live and up in Network, with this option nmap skips port detection and other things. [root@server1 ~]# nmap -sP 192.168.0.* Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-18 11:01 EST Host server1.tecmint.com (192.168.0.100) appears to be up. Host server2.tecmint.com (192.168.0.101) appears to be up. MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems) Nmap finished: 256 IP addresses (2 hosts up) scanned in 5.109 seconds ### 14. Perform a Fast Scan ### You can perform a fast scan with “**-F**” option to scans for the ports listed in the nmap-services files and leaves all other ports. [root@server1 ~]# nmap -F 192.168.0.101 Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 16:47 EST Interesting ports on server2.tecmint.com (192.168.0.101): Not shown: 1234 closed ports PORT STATE SERVICE 22/tcp open ssh 80/tcp open http 111/tcp open rpcbind 3306/tcp open mysql 8888/tcp open sun-answerbook MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems) Nmap finished: 1 IP address (1 host up) scanned in 0.322 seconds ### 15. Find Nmap version ### You can find out Nmap version you are running on your machine with “**-V**” option. [root@server1 ~]# nmap -V Nmap version 4.11 ( http://www.insecure.org/nmap/ ) You have new mail in /var/spool/mail/root ### 16. Scan Ports Consecutively ### Use the “**-r**” flag to don’t randomize. [root@server1 ~]# nmap -r 192.168.0.101 Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 16:52 EST Interesting ports on server2.tecmint.com (192.168.0.101): Not shown: 1674 closed ports PORT STATE SERVICE 22/tcp open ssh 80/tcp open http 111/tcp open rpcbind 957/tcp open unknown 3306/tcp open mysql 8888/tcp open sun-answerbook MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems) Nmap finished: 1 IP address (1 host up) scanned in 0.363 seconds 17. Print Host interfaces and Routes You can find out host interface and route information with nmap by using “**–iflist**” option. [root@server1 ~]# nmap --iflist Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 17:07 EST ************************INTERFACES************************ DEV (SHORT) IP/MASK TYPE UP MAC lo (lo) 127.0.0.1/8 loopback up eth0 (eth0) 192.168.0.100/24 ethernet up 08:00:27:11:C7:89 **************************ROUTES************************** DST/MASK DEV GATEWAY 192.168.0.0/0 eth0 169.254.0.0/0 eth0 In above output, you can see that map is listing interfaces attached to your system and their respective routes. ### 18. Scan for specific Port ### There are various options to discover ports on remote machine with Nmap. You can specify the port you want nmap to scan with “**-p**” option, by default nmap scans only **TCP** ports. [root@server1 ~]# nmap -p 80 server2.tecmint.com Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 17:12 EST Interesting ports on server2.tecmint.com (192.168.0.101): PORT STATE SERVICE 80/tcp open http MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems) Nmap finished: 1 IP address (1 host up) sca ### 19. Scan a TCP Port ### You can also specify specific port types and numbers with nmap to scan. [root@server1 ~]# nmap -p T:8888,80 server2.tecmint.com Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 17:15 EST Interesting ports on server2.tecmint.com (192.168.0.101): PORT STATE SERVICE 80/tcp open http 8888/tcp open sun-answerbook MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems) Nmap finished: 1 IP address (1 host up) scanned in 0.157 seconds ### 20. Scan a UDP Port ### [root@server1 ~]# nmap -sU 53 server2.tecmint.com Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 17:15 EST Interesting ports on server2.tecmint.com (192.168.0.101): PORT STATE SERVICE 53/udp open http 8888/udp open sun-answerbook MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems) Nmap finished: 1 IP address (1 host up) scanned in 0.157 seconds ### 21. Scan Multiple Ports ### You can also scan multiple ports using option “**-p**“. [root@server1 ~]# nmap -p 80,443 192.168.0.101 Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-18 10:56 EST Interesting ports on server2.tecmint.com (192.168.0.101): PORT STATE SERVICE 80/tcp open http 443/tcp closed https MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems) Nmap finished: 1 IP address (1 host up) scanned in 0.190 seconds ### 22. Scan Ports by Network Range ### You can scan ports with ranges using expressions. [root@server1 ~]# nmap -p 80-160 192.168.0.101 ### 23. Find Host Services version Numbers ### We can find out service’s versions which are running on remote hosts with “**-sV**” option. [root@server1 ~]# nmap -sV 192.168.0.101 Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 17:48 EST Interesting ports on server2.tecmint.com (192.168.0.101): Not shown: 1674 closed ports PORT STATE SERVICE VERSION 22/tcp open ssh OpenSSH 4.3 (protocol 2.0) 80/tcp open http Apache httpd 2.2.3 ((CentOS)) 111/tcp open rpcbind 2 (rpc #100000) 957/tcp open status 1 (rpc #100024) 3306/tcp open mysql MySQL (unauthorized) 8888/tcp open http lighttpd 1.4.32 MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems) Nmap finished: 1 IP address (1 host up) scanned in 12.624 seconds #### 24. Scan remote hosts using TCP ACK (PA) and TCP Syn (PS) #### Sometimes packet filtering firewalls blocks standard **ICMP** ping requests, in that case, we can use **TCP ACK** and **TCP Syn** methods to scan remote hosts. [root@server1 ~]# nmap -PS 192.168.0.101 Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 17:51 EST Interesting ports on server2.tecmint.com (192.168.0.101): Not shown: 1674 closed ports PORT STATE SERVICE 22/tcp open ssh 80/tcp open http 111/tcp open rpcbind 957/tcp open unknown 3306/tcp open mysql 8888/tcp open sun-answerbook MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems) Nmap finished: 1 IP address (1 host up) scanned in 0.360 seconds You have new mail in /var/spool/mail/root ### 25. Scan Remote host for specific ports with TCP ACK ### [root@server1 ~]# nmap -PA -p 22,80 192.168.0.101 Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 18:02 EST Interesting ports on server2.tecmint.com (192.168.0.101): PORT STATE SERVICE 22/tcp open ssh 80/tcp open http MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems) Nmap finished: 1 IP address (1 host up) scanned in 0.166 seconds You have new mail in /var/spool/mail/root ### 26. Scan Remote host for specific ports with TCP Syn ### [root@server1 ~]# nmap -PS -p 22,80 192.168.0.101 Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 18:08 EST Interesting ports on server2.tecmint.com (192.168.0.101): PORT STATE SERVICE 22/tcp open ssh 80/tcp open http MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems) Nmap finished: 1 IP address (1 host up) scanned in 0.165 seconds You have new mail in /var/spool/mail/root ### 27. Perform a stealthy Scan ### [root@server1 ~]# nmap -sS 192.168.0.101 Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 18:10 EST Interesting ports on server2.tecmint.com (192.168.0.101): Not shown: 1674 closed ports PORT STATE SERVICE 22/tcp open ssh 80/tcp open http 111/tcp open rpcbind 957/tcp open unknown 3306/tcp open mysql 8888/tcp open sun-answerbook MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems) Nmap finished: 1 IP address (1 host up) scanned in 0.383 seconds You have new mail in /var/spool/mail/root ### 28. Check most commonly used Ports with TCP Syn ### [root@server1 ~]# nmap -sT 192.168.0.101 Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 18:12 EST Interesting ports on server2.tecmint.com (192.168.0.101): Not shown: 1674 closed ports PORT STATE SERVICE 22/tcp open ssh 80/tcp open http 111/tcp open rpcbind 957/tcp open unknown 3306/tcp open mysql 8888/tcp open sun-answerbook MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems) Nmap finished: 1 IP address (1 host up) scanned in 0.406 seconds You have new mail in /var/spool/mail/root ### 29. Perform a tcp null scan to fool a firewall ### [root@server1 ~]# nmap -sN 192.168.0.101 Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2013-11-11 19:01 EST Interesting ports on server2.tecmint.com (192.168.0.101): Not shown: 1674 closed ports PORT STATE SERVICE 22/tcp open|filtered ssh 80/tcp open|filtered http 111/tcp open|filtered rpcbind 957/tcp open|filtered unknown 3306/tcp open|filtered mysql 8888/tcp open|filtered sun-answerbook MAC Address: 08:00:27:D9:8E:D7 (Cadmus Computer Systems) Nmap finished: 1 IP address (1 host up) scanned in 1.584 seconds You have new mail in /var/spool/mail/root That’s it with **NMAP** for now, I’ll be coming up more creative options of **NMAP** in our second part of this serious. Till then, stay tuned with us and don’t forget to share your valuable comments. -------------------------------------------------------------------------------- via: http://www.tecmint.com/nmap-command-examples/ 译者：[译者ID](https://github.com/译者ID) 校对：[校对者ID](https://github.com/校对者ID) 本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译，[Linux中国](http://linux.cn/) 荣誉推出 [1]:http://www.tecmint.com/20-linux-yum-yellowdog-updater-modified-commands-for-package-mangement/ [2]:http://www.tecmint.com/useful-basic-commands-of-apt-get-and-apt-cache-for-package-management/