Explanation:
In this scenario, there will be 14 hosts per network. The formula for calculating the number of hosts on a subnet is 2^n – 2, where n is the number of host bits in the summary mask. The n can be calculated by subtracting host bits from the total number of bits in a subnet mask (32). In this case, n would be 32 – 28 = 4.

The 192.16.100.0/28 network address would not have 30 hosts per network. The 192.16.100.0/27 network address would actually yield 30 hosts per network. In this case, n would be 32 – 27 = 5, so the number of host bits in the subnet mask would be 32 – 2, which is equal to 30.

The 192.16.100.0/28 network address would not have 6 hosts per network. The 192.16.100.0/29 network address would yield 6 hosts per network. In this case, n would be 32 – 29 = 3, so the number of host bits in the subnet mask would be 8 – 2, which is equal to 6.

The 192.16.100.0/28 network address would not have 2 hosts per network. The 192.16.100.0/30 network address would yield 2 hosts per network. In this case, n would be 32 – 30 = 2, so the number of host bits in the subnet mask would be 4 – 2, which is equal to 2.

Explanation:
The eigrp router-id command should be executed in router configuration mode to fix the issue. This command specifies a fixed router IPv4 address to the router. If this command is missing or incorrectly configured on the router, EIGRP for IPv6 will not run properly.

Another command that you should perform so that EIGRP for IPv6 runs on the routers is the no shutdown command. You should execute this command in interface configuration mode. The no shutdown command is necessary because all the interfaces with EIGRP for IPv6 enabled on them are in a shutdown state by default.

The two options stating that the ipv6 address command should be executed on the routers are incorrect. EIGRP for IPv6 can be configured on router interfaces without explicitly specifying a global unicast IPv6 address. If you specify the ipv6 enable command, as in this scenario, then the IPv6 address command is not required.

The option stating that the eigrp router-id command should be executed in interface configuration mode is incorrect. This command should be executed in router configuration mode instead of interface or global configuration modes.

Explanation:
You could either configure separate VLANs for each department or configure separate subnets for each department. Either approach has the effect of restricting each department’s traffic to its local subnet or VLAN, unless you configure and allow inter-VLAN routing.

VLANs logically divide a switched network into multiple independent broadcast domains. Broadcast traffic within one VLAN will never be sent to hosts in other VLANs. In this respect, VLANs operate exactly as subnets do. The only way for hosts in different VLANs to communicate is through a router or multilayer switch configured to perform inter-VLAN routing between the VLANs.

The VLAN Trunking Protocol (VTP) is used to synchronize VLAN databases across multiple switches, and is not a method for isolating departmental traffic.

Collision domains cannot be used to isolate traffic between departments. Multiple departments cannot share a collision domain when using switches. Every port on a switch is a separate collision domain, which allows the switch to forward more than one frame at a time. This also reduces collisions, since each host is therefore in a separate collision domain. The switch processes data based only on MAC addresses, and has no knowledge of which host is in which IP subnet or department.

Trunk links are used to connect switches to other switches and to routers for the purpose of carrying traffic from multiple VLANs, and are not a method of isolating traffic between different departments.

Explanation:
The full duplex mode of transmission is not provided by flow control. Full duplex transmission is an Ethernet concept where hosts are able to send and receive at the same time. There are no collisions in a full-duplex Ethernet network. A dedicated switch port is required for each node in a full-duplex Ethernet network. Both the host’s NIC and the switch port must be capable of operating in full-duplex mode. When full duplex is implemented, no collisions will occur on the link between the switch and the device. That will be one error condition that can be removed from consideration when troubleshooting a full duplex link.

Flow control is a function that prevents network congestion. It does so by ensuring that the transmitting device does not flood the receiving device with data. The following statements are true regarding flow control:

– Controls the amount of data which the sender can send to the receiver.
– Uses buffering, transmitting source-quench messages, and windowing to handle network congestion.
– Determines the rate at which the data is transmitted between the sender and receiver.
– Types of flow control include windowing, buffering, and congestion avoidance.

Flow control generally operates at the Transport layer in the OSI model. The Transport layer is responsible for error-free and sequential delivery of data. This layer is used to manage data transmission between devices.

Buffering is a method by which network devices use to save temporary overflows of excess data into the memory. The data is stored in the memory until it is processed.

Source-quench messages are used by the devices that receive the data to avoid buffer overflow.
Windowing is a scheme in which an acknowledgement is required by the source device from the destination after the transmission of a fixed number of packets.

Explanation:
A router allows communication across separate broadcast domains. A broadcast domain is group of hosts and network devices in which a broadcast frame sent by one host can be received by all of the other hosts in the broadcast domain. A router determines the path to other destination networks, and forwards data packets to the next hop along this path. A router operates at Layer 3 of the Open System Interconnect (OSI) layered communication model and uses an Internet Protocol (IP) address hierarchy to identify and route data through source and destination devices.

A switch does not allow communication across separate broadcast domains. A switch creates collision domains and enables communications across different collision domains. A collision domain is a logical group of hosts and network devices where packets can potentially collide with one another, causing a communications disruption. Switches forward broadcasts so they do not form a separate broadcast domain unless Virtual LANs (VLANs) are created.

A hub does not allow communication across separate broadcast domains. A hub transmits frames, which means that they neither form separate collision or broadcast domains nor allow communication across these domains. Hubs are multiport devices that allow consolidation of various LAN segments and amplify signals that pass through them. Hubs operate at OSI Layer 1.

An access point does not allow communication across separate broadcast domains. Access points (APs) are OSI Layer 2 wireless hubs that allow client hosts to connect to the backbone network wirelessly.

Explanation:
Network Control Protocol (NCP) is responsible for negotiating upper-layer protocols that will be carried across the PPP connection. NCP defines how the two PPP peers negotiate with the network layer protocols, such as IP and IPX, which will be used across the PPP connection.

Link Control protocol (LCP) is not responsible for negotiating upper-layer protocols that will be carried across a PPP connection. Link Control protocol (LCP) has the primary responsibility of negotiating and maintaining the PPP connection. LCP, defined in Request for Comments (RFCs) 1548 and 1570, has the primary responsibility to establish, configure, authenticate, and test a PPP connection. LCP negotiates the following when setting up a PPP connection:

– Authentication method used (PAP or CHAP), if any
– Compression algorithm used (Stacker or Predictor), if any
– Callback phone number to use, if defined
– Multilink; other physical connections to use, if configured

Local Management Interface (LMI) is not responsible for negotiating upper-layer protocols that will be carried across the PPP connection. LMI is a characteristic of a frame relay connection. There are three types of LMIs supported by Cisco routers:
– Cisco
– ANSI Annex D
– Q933-A Annex A

LMI has nothing to do with PPP connections.

Integrated Services Digital Network (ISDN) is a type of WAN connection and has nothing to do with PPP connections.

Explanation:
The Serial 0 is up, line protocol is down statement in the output signifies the following:

– There are no problems with the physical connectivity.
– There is a configuration problem in the local or remote router.
– The remote router might not be sending the keep-alives.
– There may be a problem with the leased lines such as line noise and a malfunctioning switch.
– There is an incorrect configuration of the CSU/DSU, which can cause timing issues on the cable.
– The local or remote CSU/DSU might have failed.

The option stating that the shutdown interface command is present in the router configuration is incorrect because if the shutdown interface command is present in the router configuration, the message displayed would be Serial 0 is administratively down, line protocol is down.

The option stating that a cable is unplugged is incorrect because that would be indicated by Serial 0 is down, line protocol is down. Physical problems such as a bad cable or cable unplugged are addressed in the first part of the output (serial0 is up/down).

The option stating that the message refers to normal operation of the interface is incorrect because the line protocol is shown as down, which indicates a problem. Objective:

Explanation:
The show interfaces trunk command displays a list of interfaces currently operating as trunks, and their configuration (such as supported VLANs or frame tagging method).

Switch# show interfaces trunk
Port Mode Encapsulation Status Native vlan Gi0/1 desirable 802.1q trunking 1
Gi0/2 desirable 802.1q trunking 1

Port Vlans allowed on trunk Gi0/1 1-4094
Gi0/2 1-4094
<

>

This output indicates that switch ports Gi0/1 and Gi0/2 are both currently operating as trunks (Status), and that 802.1q frame tagging is being used on the trunk links.

The remaining options are incorrect because they are not valid Cisco IOS commands.

Explanation:
The show ip ospf command is used to view information about the OSPF routing processes. It does so by displaying the collection of link states present in the database.

The show ip ospf database command is incorrect because this command is used to view the OSPF database for a specific router.

The show ip ospf statistics command is incorrect because this command is no longer valid in IOS version 12.4.

The show ip ospf traffic command is incorrect because this command is no longer valid in IOS version 12.4.