N$6\mathrm{.}5.$ Does a SYN flooding attack cause the victim server to freeze?

N$6\mathrm{.}6.$ In the SYN flooding attack, why do we randomize the source IP address? Why can't we

just use the same IP address?

N$6\mathrm{.}7.$ What will happen if the spoofed source IP address in a SYN flooding attack does

belong to a machine that is currently running?

N$6\mathrm{.}8.$ An attacker launches a SYN flooding attack against the telnet server on a target

ma$-$ chine. This particular telnet server listens to two ports, port $23$ and port $8023.$ The

attack is only targeting the default telnet port $23.$ When the attack is undergoing, can

people still be able to telnet to the server using port $8023?$

N$6\mathrm{.}9.$ Can we launch a SYN flooding attack from a computer without using the root privilege?

N$6\mathrm{.}10.$ Why do we choose to fill up the memory used for half$-$open connections, why cannot

we directly target the memory used for holding full connections? The latter requires more

memory, so the resource is much easier to exhaust.

N$6\mathrm{.}11.$ If TCP always uses a fixed sequence number $($e$.$g$.,$ zero$)$ in its

SYN $+$ ACK packet during the three$-$way handshake protocol, please

describe how you can conduct a denial$-$ of$-$service attack on the TCP

server. Your objective is different from the SYN flooding attack: you

want to cause the server to establish connections with many non$-$

existing computers, and thus exhausting the server's resources,

especially its memory.

N$6\mathrm{.}12.$ All the information that a server needs to know about a

connection is not only con$-$ tained in the SYN packet, but

also in the final ACK packet from the client. Therefore,

information$-$wise, there is no need to allocate a buffer to save

the information about half$-$open connections. If we get rid of

this buffer, the SYN flooding attack will not be effective any

more. Do you agree with such a statement or not. Please

justify your answer.

N$6\mathrm{.}13.$ To reset a connection between two remote machines, i$.$e$.,$ we

will not be able to see the packets between these two

machines, what are the main challenges?

N$6\mathrm{.}16.$ There is an active connection between a Telnet client $(10\mathrm{.}0\mathrm{.}2\mathrm{.}5)$ and a Telnet server

$(10\mathrm{.}0\mathrm{.}2\mathrm{.}9).$ The server has just acknowledged a sequence number $1000,$ and the client has

just acknowledged a sequence number $3000.$ An attacker wants to launch the TCP session

hijacking attack on the connection, so he can execute a command on the server. He is on the

same local area network as these two computers. You need to construct a TCP packet for the

attacker. Please fill in the following fields:

$$ Source IP and Destination IP

$$ Source port and Destination port

$$ Sequence number

$$ The TCP data field.