A distributed port scan operates by a blocking access

QUESTION 55
A distributed port scan operates by:
A. Blocking access to the scanning clients by the targeted host
B. Using denial-of-service software against a range of TCP ports
C. Blocking access to the targeted host by each of the distributed scanning clients
D. Having multiple computers each scan a small number of ports, then correlating the results
Correct Answer:
Section: (none)
Explanation
Explanation/Reference:
Explanation:
Think of dDoS (distributed Denial of Service) where you use a large number of computers to create
simultaneous traffic against a victim in order to shut them down.
D
QUESTION 56
You want to know whether a packet filter is in front of 192.168.1.10. Pings to 192.168.1.10 don't get
answered.
A basic nmap scan of 192.168.1.10 seems to hang without returning any information. What should you do
next?

C
Section: (none)
Explanation
Explanation/Reference:
QUESTION 57
What does ICMP (type 11, code 0) denote?
B
QUESTION 58
An nmap command that includes the host specification of 202.176.56-57.* will scan _______ number of
hosts.
C
QUESTION 59
A specific site received 91 ICMP_ECHO packets within 90 minutes from 47 different sites. 77 of the
ICMP_ECHO packets had an ICMP ID:39612 and Seq:57072. 13 of the ICMP_ECHO packets had an
ICMP
ID:0 and Seq:0. What can you infer from this information?
A. The packets were sent by a worm spoofing the IP addresses of 47 infected sites
B. ICMP ID and Seq numbers were most likely set by a tool and not by the operating system
C. All 77 packets came from the same LAN segment and hence had the same ICMP ID and Seq number
D. 13 packets were from an external network and probably behind a NAT, as they had an ICMP ID 0 and
Correct Answer:
Section: (none)
Seq
0
B
Explanation
Explanation/Reference: