Free 312-50 Exam Braindumps (page: 31)

Page 30 of 191

Jack is conducting a port scan of a target network. He knows that his target network has a web server and that a mail server is up and running. Jack has been sweeping the network but has not been able to get any responses from the remote target. Check all of the following that could be a likely cause of the lack of response?

  1. The host might be down
  2. UDP is filtered by a gateway
  3. ICMP is filtered by a gateway
  4. The TCP window Size does not match
  5. The destination network might be down
  6. The packet TTL value is too low and can’t reach the target

Answer(s): A,C,E,F

Explanation:

Wrong answers is B and D as sweeping a network uses ICMP



War dialing is one of the oldest methods of gaining unauthorized access to the target systems, it is one of the dangers most commonly forgotten by network engineers and system administrators. A hacker can sneak past all the expensive firewalls and IDS and connect easily into the network. Through wardialing an attacker searches for the devices located in the target network infrastructure that are also accessible through the telephone line.
‘Dial backup’ in routers is most frequently found in networks where redundancy is required. Dial-on-demand routing(DDR) is commonly used to establish connectivity as a backup.
As a security testers, how would you discover what telephone numbers to dial-in to the router?

  1. Search the Internet for leakage for target company’s telephone number to dial-in
  2. Run a war-dialing tool with range of phone numbers and look for CONNECT Response
  3. Connect using ISP’s remote-dial in number since the company’s router has a leased line connection established with them
  4. Brute force the company’s PABX system to retrieve the range of telephone numbers to dial-in

Answer(s): B

Explanation:

Use a program like Toneloc to scan the company’s range of phone numbers.



The FIN flag is set and sent from host A to host B when host A has no more data to transmit (Closing a TCP connection). This flag releases the connection resources. However, host A can continue to receive data as long as the SYN sequence number of transmitted packets from host B are lower than the packet segment containing the set FIN flag.

  1. True
  2. False

Answer(s): A

Explanation:

For sequence number purposes, the SYN is considered to occur before the first actual data octet of the segment in which it occurs, while the FIN is considered to occur after the last actual data octet in a segment in which it occurs. So packets receiving out of order will still be accepted.



Which type of scan does not open a full TCP connection?

  1. Stealth Scan
  2. XMAS Scan
  3. Null Scan
  4. FIN Scan

Answer(s): A

Explanation:

Stealth Scan: Instead of completing the full TCP three-way-handshake a full connection is not made. A SYN packet is sent to the system and if a SYN/ACK packet is received it is assumed that the port on the system is active. In that case a RST/ACK will be sent which will determined the listening state the system is in. If a RST/ACK packet is received, it is assumed that the port on the system is not active.






Post your Comments and Discuss EC-Council 312-50 exam with other Community members:

312-50 Discussions & Posts