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Topic 3, Scanning
What are twp types of ICMP code used when using the ping command?
A.
It uses types 0 and 8.
B.
It uses types 13 and 14.
C.
It uses types 15 and 17.
D.
The ping command does not use ICMP but uses UDP.
It uses types 0 and 8.
Explanation: ICMP Type 0 = Echo Reply, ICMP Type 8 = Echo
You ping a target IP to check if the host is up. You do not get a response. You
suspect ICMP is blocked at the firewall. Next you use hping2 tool to ping the target
host and you get a response. Why does the host respond to hping2 and not ping
packet?
[ceh]# ping 10.2.3.4
PING 10.2.3.4 (10.2.3.4) from 10.2.3.80 : 56(84) bytes of data.
-- 10.2.3.4 ping statistics --
3 packets transmitted, 0 packets received, 100% packet loss
[ceh]# ./hping2 -c 4 -n -i 2 10.2.3.4
HPING 10.2.3.4 (eth0 10.2.3.4): NO FLAGS are set, 40 headers +
0 data bytes
len=46 ip=10.2.3.4 flags=RA seq=0 ttl=128 id=54167 win=0 rtt=0.8 ms
len=46 ip=10.2.3.4 flags=RA seq=1 ttl=128 id=54935 win=0 rtt=0.7 ms
len=46 ip=10.2.3.4 flags=RA seq=2 ttl=128 id=55447 win=0 rtt=0.7 ms
len=46 ip=10.2.3.4 flags=RA seq=3 ttl=128 id=55959 win=0 rtt=0.7 ms
-- 10.2.3.4 hping statistic --
4 packets tramitted, 4 packets received, 0% packet loss
round-trip min/avg/max = 0.7/0.8/0.8 ms
A.
ping packets cannot bypass firewalls
B.
you must use ping 10.2.3.4 switch
C.
hping2 uses TCP instead of ICMP by default
D.
hping2 uses stealth TCP packets to connect
hping2 uses TCP instead of ICMP by default
Explanation: Default protocol is TCP, by default hping2 will send tcp headers to target
host's port 0 with a winsize of 64 without any tcp flag on. Often this is the best way to do an
'hide ping', useful when target is behind a firewall that drop ICMP. Moreover a tcp null-flag
to port 0 has a good probability of not being logged.
Name two software tools used for OS guessing.(Choose two.)
A.
Nmap
B.
Snadboy
C.
Queso
D.
UserInfo
E.
NetBus
Nmap
Queso
Explanation: Nmap and Queso are the two best-known OS guessing programs. OS
guessing software has the ability to look at peculiarities in the way that each vendor
implements the RFC's. These differences are compared with its database of known OS
fingerprints. Then a best guess of the OS is provided to the user.
What ICMP message types are used by the ping command?
A.
Timestamp request (13) and timestamp reply (14)
B.
Echo request (8) and Echo reply (0)
C.
Echo request (0) and Echo reply (1)
D.
Ping request (1) and Ping reply (2)
Echo request (8) and Echo reply (0)
Explanation: ICMP Type 0 = Echo Reply, ICMP Type 8 = Echo
When Nmap performs a ping sweep, which of the following sets of requests does it
send to the target device?
A.
ICMP ECHO_REQUEST & TCP SYN
B.
ICMP ECHO_REQUEST & TCP ACK
C.
ICMP ECHO_REPLY & TFP RST
D.
ICMP ECHO_REPLY & TCP FIN
ICMP ECHO_REQUEST & TCP ACK
Explanation: The default behavior of NMAP is to do both an ICMP ping sweep (the usual
kind of ping) and a TCP port 80 ACK ping sweep. If an admin is logging these this will be
fairly characteristic of NMAP.
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