Before Starting scanning and its methodology we must start with discussing types of scans.
First of all there are 3 types of scans possible based on their operation performed.
These are Port Scanning, Network Scanning and vulnerability scanning.
1.Port Scanning is used to determine open ports and services.
2.Network Scanning is used to locate working IP Addresses from a list and find out which are more useful.
3.Vulnerability Scanning is for knowing the weaknesses in a network computers.
Know,Let us know about some popular services and ports used by them.FTP uses port no 21, Telnet uses port no 23, HTTP uses port 80, SMTP-25,POP3-110,HTTPS-443.
Scanning Methodology:-
1.Check for Live Systems.
we can check for live systems by performing Ping Sweep of IP Addresses.The systems responding to PING are active or live others might be Inactive or possibility of firewalls.
2.Check Open Ports.
3.Service Identification.
4.banner Grabbing or OS FingerPrinting.
5.Vulnerability Scanning.
NOTE:-
ICMP Scanning or Ping Sweep :-
Sending ICMP requests to all hosts on network to determine which are up and responding.It runs parallel on all systems because it can be run on all Systems simultaneously.
CounterMeasures to Port Scanning:-
Following steps could be followed:-
1.Implementation Of Intrusion Detection Systems or firewalls, should be followed.
2.After implementation of IDS or firewalls perform port scanning using tools such as Pinger, Friendly Pinger, WS_PING_PRO and many more so as to know whether firewall correctly works or not.
3.Check whether firewall able to detect probes set up by Port scanning tool.
It is to be noted that firewall must scan both data and packet not only TCP Header to determine whether traffic is allowed to pass through Firewall.
4.Network IDS should be used to hold on Operating System Detection Methods.
5.Onlu Needed Ports should be opened and rest closed.
First of all there are 3 types of scans possible based on their operation performed.
These are Port Scanning, Network Scanning and vulnerability scanning.
1.Port Scanning is used to determine open ports and services.
2.Network Scanning is used to locate working IP Addresses from a list and find out which are more useful.
3.Vulnerability Scanning is for knowing the weaknesses in a network computers.
Know,Let us know about some popular services and ports used by them.FTP uses port no 21, Telnet uses port no 23, HTTP uses port 80, SMTP-25,POP3-110,HTTPS-443.
Scanning Methodology:-
1.Check for Live Systems.
we can check for live systems by performing Ping Sweep of IP Addresses.The systems responding to PING are active or live others might be Inactive or possibility of firewalls.
2.Check Open Ports.
3.Service Identification.
4.banner Grabbing or OS FingerPrinting.
5.Vulnerability Scanning.
NOTE:-
ICMP Scanning or Ping Sweep :-
Sending ICMP requests to all hosts on network to determine which are up and responding.It runs parallel on all systems because it can be run on all Systems simultaneously.
CounterMeasures to Port Scanning:-
Following steps could be followed:-
1.Implementation Of Intrusion Detection Systems or firewalls, should be followed.
2.After implementation of IDS or firewalls perform port scanning using tools such as Pinger, Friendly Pinger, WS_PING_PRO and many more so as to know whether firewall correctly works or not.
3.Check whether firewall able to detect probes set up by Port scanning tool.
It is to be noted that firewall must scan both data and packet not only TCP Header to determine whether traffic is allowed to pass through Firewall.
4.Network IDS should be used to hold on Operating System Detection Methods.
5.Onlu Needed Ports should be opened and rest closed.
