CEHv8 BOOTCAMP: MODULE 03-SCANNING NETWORKS_SET-1 Flashcards
What does network scanning refer to?
A set of procedures for identifying hosts, ports, and services in a network.
What are the 4 objectives of network scanning?
- To discover live hosts, IP address, and open ports of live hosts.
- To discover operating systems and system architecture.
- To discover services running on hosts.
- To discover vulnerabilities in the hosts.
A ping scan involves sending what to a host?
ICMP ECHO requests.
During a ping scan; if the host is live what will it return?
ICMP ECHO reply.
What is a ping scan useful for?
Locating active devices, or determining if ICMP is passing through a firewall.
What is a ping sweep used for?
To determine the live host from a range of IP addresses by sending ICMP ECHO requests for multiple hosts.
If a target host is live during a ping sweep what will be returned?
ICMP ECHO reply.
A ping sweep can be used to create what?
An inventory of live systems in the subnet.
How can attackers calculate the number of hosts present in the subnet?
Using subnet mask calculators.
Describe an Angry IP Scanner.
pings each IP to check if it’s live then optionally resolves it’s host name.
Describe SolarWinds Engineer’s Toolset.
- A ping sweep that enables scanning a range of IP address to identify which IP address are in use and which ones are currently free.
- Performs reverse DNS lookup.
What does TCP use to establish a connection between server and client?
A 3-way handshake.
Describe a 3-way handshake.
- Computer A initials a connection to the server via a packet with only the SYN flag set.
- The server replies with a packet with both the SYN and the ACK flags set.
- The client responds back to the server with a single ACK packet.
What are the 6 TCP communication flags?
- Urgent (URG)
- Finish (FIN)
- Reset (RST)
- Push (PSH)
- Acknowledgement (ACK)
- Synchronize (SYN)
What is the Urgent (URG) TCP Flag?
Data contained in the packet should be processed immediately.
