1. Nmap Experiment

2. Outline
Introduction
NMAP - NMAP advantages - NMAP capability of support
NMAP Install - Install of under Windows - Install of under Linux
NMAP Experiment - Use NMAP - Parameter：-sT - Parameter：-sS
Conclusions

3. Introduction A Port Scanner software on unix
By NMAP scan - Quickly know remote host executive services - Guess remote host’s Operation System & Version - Subnet scanning =>To detect the subnet on which hosts and each of detection of its services

4. Nmap pros & function Nmap advantages Nmap function
- Support scanning of variety protocols - Support most of existing system - Operate interface simply - Simple instructions , powerful functions - Free software
Nmap function
- TCP SYN scanning - TCP ftp proxy scanning - ICMP scanning - TCP ping scanning

5. TCP Flag Definition Flag SYN The beginning of a connection ACK
Acknowledge receipt of a previous packet or transmission
FIN
Close a TCP connection
RST
Abort a TCP connection

6. Three-way handshake Connect Disconnect Client Server Client Server SYN
FIN
SYN/ACK
ACK/FIN
ACK
ACK
Connection Established
Connection
Closed

7. Nmap Install

8. Windows

9. Linux Fedora : (Root Permission) yum install Nmap
or wget
Ubuntu : sudo apt-get install Nmap

10. Scanning for TCP Ports
Instruction : nmap –sT Target host

11. SYN Scan Instruction : nmap –sS Target host Nmap sends to Host Port
Nmap receives from Host Port
Nmap Assumes
SYN
SYN/ACK
Port is open
Host is up
RST
Port is closed
Nothing
Port is blocked by firewall
Or Host is down

12. Scanning Host Port
Instruction : namp –p [1-1024] Target host

13. OS detection
Instruction : nmap –O Target host

14. Conclusions Nmap is a useful and free security detective tool
Through Nmap provide detailed information that can understand host deeply and also avoid unexpected security vulnerabilities
Other scanning tools - Netscantools - Superscan - IPEYE - WUPS