CCNA 2 v6 RSE Chapter 4 Exam Online

A collapsed core design is appropriate for a small, single building business. This type of design uses two layers (the collapsed core and distribution layers consolidated into one layer and the access layer). Larger businesses use the traditional three-tier switch design model.

Maintaining three separate network tiers is not always required or cost-efficient. All network designs require an access layer, but a two-tier design can collapse the distribution and core layers into one layer to serve the needs of a small location with few users.

One of the basic functions of the distribution layer of the Cisco Borderless Architecture is to perform routing between different VLANs. Acting as a backbone and aggregating campus blocks are functions of the core layer. Providing access to end user devices is a function of the access layer.

A converged network provides a single infrastructure that combines voice, video, and data. Analog phones, user data, and point-to-point video traffic are all contained within the single network infrastructure of a converged network.

A converged network has only one physical network to install and manage. This results in substantial savings over the installation and management of separate voice, video, and data networks.

By looking at the graphic in 1.1.2.2 #2 and #3 and comparing those photos to the graphics used in the Cisco switch design model shown in 1.1.1.5 #2, you can see that the smaller rack unit fixed configuration switch is used as an access layer switch. The modular configuration switch would be used at the distribution and core layers.

Fixed-configuration switches, although lower in price, have a designated number of ports and no ability to add ports. They also typically provide fewer high-speed ports. In order to scale switching on a network that consists of fixed-configuration switches, more switches need to be purchased. This increases the number of power outlets that need to be used. Modular switches can be scaled simply by purchasing additional line cards. Bandwidth aggregation is also easier, because the backplane of the chassis can provide the bandwidth that is needed for the switch port line cards.

When a switch receives a frame with a source MAC address that is not in the MAC address table, the switch will add that MAC address to the table and map that address to a specific port. Switches do not use IP addressing in the MAC address table.

A switch provides microsegmentation so that no other device competes for the same Ethernet network bandwidth.

Cisco LAN switches use the MAC address table to make decisions of traffic forwarding. The decisions are based on the ingress port and the destination MAC address of the frame. The ingress port information is important because it carries the VLAN to which the port belongs.

Because this is a broadcast frame, SW1 will send it to all ports except to the ingress one (the port in which the request was received).

A switch builds a MAC address table of MAC addresses and associated port numbers by examining the source MAC address found in inbound frames. To forward a frame onward, the switch examines the destination MAC address, looks in the MAC address for a port number associated with that destination MAC address, and sends it to the specific port. If the destination MAC address is not in the table, the switch forwards the frame out all ports except the inbound port that originated the frame.

When a switch powers on, the MAC address table is empty. The switch builds the MAC address table by examining the source MAC address of incoming frames. The switch forwards based on the destination MAC address found in the frame header. If a switch has no entries in the MAC address table or if the destination MAC address is not in the switch table, the switch will forward the frame out all ports except the port that brought the frame into the switch.

By dividing the one big network into two smaller network, the network administrator has created two smaller broadcast domains. When a broadcast is sent on the network now, the broadcast will only be sent to the devices on the same Ethernet LAN. The other LAN will not receive the broadcast.

A router defines a broadcast boundary, so every link between two routers is a broadcast domain. In the exhibit, 4 links between routers make 4 broadcast domains. Also, each LAN that is connected to a router is a broadcast domain. The 4 LANs in the exhibit result in 4 more broadcast domains, so there are 8 broadcast domains in all.

Switches provide microsegmentation so that one device does not compete for the same Ethernet network bandwidth with another network device, thus practically eliminating collisions. A high port density switch provides very fast connectivity for many devices.

Layer 1 and 2 devices (LAN switch and Ethernet hub) and access point devices do not filter MAC broadcast frames. Only a Layer 3 device, such as a router, can divide a Layer 2 broadcast domain.

In a Layer 2 broadcast frame, the destination MAC address (contained in the frame header) is set to all binary ones, therefore, the format of FF-FF-FF-FF-FF-FF. The binary format of 11 in hexadecimal is 00010001. 255.255.255.255 and 0.0.0.0 are IP addresses.

In Cisco LAN switches, the microsegmentation makes it possible for each port to represent a separate segment and thus each switch port represents a separate collision domain. This fact will not change when multiple switches are interconnected. However, LAN switches do not filter broadcast frames. A broadcast frame is flooded to all ports. Interconnected switches form one big broadcast domain.

The term port density represents the number of ports available in a switch. A one rack unit access switch can have up to 48 ports. Larger switches may support hundreds of ports.

A switch has the ability of creating temporary point-to-point connections between the directly-attached transmitting and receiving network devices. The two devices have full-bandwidth full-duplex connectivity during the transmission.