Answer: A

Explanation:

Different VLANs can't communicate with each other, they can communicate with the help of Layer3 router. Hence, it is needed to connect a router to a switch, then make the sub- interface on the router to connect to the switch, establishing Trunking links to achieve communications of devices which belong to different VLANs.

When using VLANs in networks that have multiple interconnected switches, you need to use VLAN trunking between the switches. With VLAN trunking, the switches tag each frame sent between switches so that the receiving switch knows to what VLAN the frame belongs. End user devices connect to switch ports that provide simple connectivity to a single VLAN each. The attached devices are unaware of any VLAN structure.

By default, only hosts that are members of the same VLAN can communicate. To change this and allow inter-VLAN communication, you need a router or a layer 3 switch.

Here is the example of configuring the router for inter-vlan communication

RouterA(config)#int f0/0.1 RouterA(config-subif)#encapsulation ? dot1Q IEEE 802.1Q Virtual LAN

RouterA(config-subif)#encapsulation dot1Q or isl VLAN ID RouterA(config-subif)# ip address x.x.x.x y.y.y.y

Answer: D

Explanation:

An address conflict occurs when two hosts use the same IP address. During address assignment, DHCP checks for conflicts using ping and gratuitous ARP. If a conflict is detected, the address is removed from the pool. The address will not be assigned until the administrator resolves the conflict.

(Reference: http://www.cisco.com/en/US/docs/ios/12_1/iproute/configuration/guide/1cddhcp.html)

Answer: C

Explanation:

The first lines of the message show that a configuration change was made, and that the fa0/1 interface changed to a state of administratively down. This can only be done by issuing the shutdown command. The last line indicates that this caused an EIGRP neighbor adjacency to go down.

Answer: B,C,F

Explanation:

The subnet mask in use is 255.255.255.128: This is subnet mask will support up to 126 hosts, which is needed.

The IP address 172.16.1.25 can be assigned to hosts in VLAN1: The usable host range in this subnet is 172.16.1.1-172.16.1.126

The LAN interface of the router is configured with multiple IP addresses: The router will need 2 subinterfaces for the single physical interface, one with an IP address that belongs in each VLAN.

Answer: B,E

Answer: D

Explanation:

Standard ACL’s only examine the source IP address/mask to determine if a match is made. Extended ACL’s examine the source and destination address, as well as port information.

Answer: C,D

Explanation:

We can verify whether port security has been configured by using the “show running- config” or “show port-security interface” for more detail. An example of the output of “show port-security interface” command is shown below:

Answer: A,B,C

Explanation:

NetFlow has a reputation for increasing CPU utilization on your network devices. Cisco's performance testing seems to indicate that newer hardware can accommodate this load pretty well, but you will still want to check it out before you turn on the feature. Some symptoms of high CPU utilization are very large jitter and increased delay. Services running on the device may also be affected.

Another thing to keep in mind is the amount of data you're going to be sending across the network. Depending on how much traffic you have and how you configure it, the traffic can be substantial. For example, you may not want to send NetFlow data from a datacenter switch to a NetFlow collector on the other side of a small WAN circuit. Also bear in mind that the flows from aggregating large numbers of devices can add up.

Reference: http://searchenterprisewan.techtarget.com/tip/How-the-NetFlow-protocol- monitors-your-WAN

Answer: B,E

Explanation:

Subnetting is used to break the network into smaller more efficient subnets to prevent excessive rates of Ethernet packet collision in a large network. Such subnets can be arranged hierarchically, with the organization's network address space (see also Autonomous System) partitioned into a tree-like structure. Routers are used to manage traffic and constitute borders between subnets.

A routing prefix is the sequence of leading bits of an IP address that precede the portion of the address used as host identifier. In IPv4 networks, the routing prefix is often expressed as a "subnet mask", which is a bit mask covering the number of bits used in the prefix. An IPv4 subnet mask is frequently expressed in quad-dotted decimal representation, e.g., 255.255.255.0 is the subnet mask for the 192.168.1.0 network with a 24-bit routing prefix (192.168.1.0/24).

Answer: C

Explanation:

Since there is one class C network that means 256 total IP addresses. Since we need 7 LAN blocks and we cannot use the first one (subnet 0) we take 256/8=32 hosts. However, since we need to reserve the network and broadcast addresses for each of these subnets, only 30 total IP addresses are usable.