Question

 

Select the correct statement(s) regarding network physical and logical topologies.

		a. a network’s physical topology must always be the same as its logical one
		b. the physical topology addresses how devices are connected, while a logical topology addresses how devices actually communicate to one another
		c. only guided networks have physical and logical topologies
		d. b and c are correct statements

Select the correct statement(s) regarding shared Ethernet LANs.

		a. all nodes on a shared Ethernet LAN must have the ability to read the address of all incoming packets
		b. CSMA/CD is always required on a shared Ethernet LAN
		c. only guided medium is used in a shared Ethernet LAN
		d. all statements are correct

Answer 1

First question
The option D is correct

A.false
A network's logical topology is not necessarily the same as its physical topology. For example, the original twisted pair Ethernet using repeater hubs was a logical bus topology carried on a physical star topology.

B.True
The physical topology addressed the way you physically lay out the network, like a map, and the logical topology is the way the information flows on the network.
A logical topology addresed that how devices appear connected to the user. A physical topology is how they are actually interconnected with wires and cables. For example, in a shared Ethernet network that uses hubs rather than switches, the logical topology appears as if every node is connected to a common bus that runs from node to node

C.true
only guided networks have physical and logical topologies

So on that all basis option d is true that
D.option b and c is true.

Second question

Option D is correct.

Option A.is true
On a shared Ethernet LAN all nodes connect to a common medium. As such, a transmission from a single node is broadcast to all connected nodes. This requires each node to have the ability to read the addressof incoming packets in order to determine if it belongs to them.

Option b is True
Shared ethernet lan using the access technique CSMA / CD. So CSMA / CD is always required on sheared ethernet lan.

Option c is true

Option c.yes that only guided medium is used in a shared Ethernet LAN beause.the waves are guided along a physical path; examples of guided media include phone lines, twisted pair cables, coaxial cables, and optical fibers and the sheared ethernet lan implementing technical standard access to physical media by the IEEE 802.3 working group under the name MAC access (Medium Access Control).

So on that basis the option d is true that
D. All statement are correct.