Answer:
d. ICMP Echo Reply (type 0)
Explanation:
ICMP or internet control message protocol is an Internet layer protocol in the TCP/IP suite. It works together with routing devices like the router to send messages based on results sensed in the network.
The RFC 1122 has stated that the ICMP server and end user application be configured or installed in user devices, for receiving and sending ICMP echo request packets and reply. The process is called pinging.
For an attacker to implement ping of ping, he needs to confirm if the target user in live by sending an ICMP echo request packet type 8, to receive an ICMP echo reply type0.
Answer:
Option B i.e., Circuit level gateways only enable data to be inserted into a network which is the product of system requests within the network.
Explanation:
In the above question, some details are missing in the question that is options.
Option B is valid because Circuit level gateways are not the transmission inspection, always require information into such a server resulting through system appeal inside the server through maintaining a record for connections that are sent into the server and only enabling information in this is in answer to such queries.
Other options are incorrect because they are not true according to the following scenario.
<u>Efferent Neurons:</u> efferent neurons are motor neurons that carry neural impulses away from the central nervous systme and towards muscles to cause movement.
<u>Interneurons: </u> a neuron which transmits impulses between other neurons, especially as part of a reflex arc
<u>Astrocytes:</u> Astrocytes are the most numerous cell type within the central nervous system (CNS) and perform a variety of tasks, from axon guidance and synaptic support, to the control of the blood brain barrier and blood flow. To perform these roles, there is a great variety of astrocytes.
Explanation: