Answer: B,D 

Explanation: 

Using a firewall is a must for networks of any size to protect the internal network from outside threats and unauthorized access. SSH traffic is encrypted while telnet is not, so it is always recommended to use SSH. 

Answer: D 

Explanation: 

The first step to deploy NAT is to define NAT inside and outside interfaces. You may find it easiest to define your internal network as inside, and the external network as outside. However, the terms internal and external are subject to arbitration as well. This figure shows an example of this. 

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Reference: http://www.cisco.com/c/en/us/support/docs/ip/network-address-translation-nat/13772-12.html#topic2 

Answer: B 

Explanation: DHCPv6 Technology Overview IPv6 Internet Address Assignment Overview 

IPv6 has been developed with Internet Address assignment dynamics in mind. Being aware that IPv6 Internet addresses are 128 bits in length and written in hexadecimals makes automation of address-assignment an important aspect within network design. These attributes make it inconvenient for a user to manually assign IPv6 addresses, as the format is not naturally intuitive to the human eye. To facilitate address assignment with little or no human intervention, several methods and technologies have been developed to automate the process of address and configuration parameter assignment to IPv6 hosts. The various IPv6 address assignment methods are as follows: 

1. 

Manual Assignment An IPv6 address can be statically configured by a human operator. However, manual assignment is quite open to errors and operational overhead due to the 128 bit length and hexadecimal attributes of the addresses, although for router interfaces and static network elements and resources this can be an appropriate solution. 

2. 

Stateless Address Autoconfiguration (RFC2462) Stateless Address Autoconfiguration (SLAAC) is one of the most convenient methods to assign Internet addresses to IPv6 nodes. This method does not require any human intervention at all from an IPv6 user. If one wants to use IPv6 SLAAC on an IPv6 node, it is important that this IPv6 node is connected to a network with at least one IPv6 router connected. This router is configured by the network administrator and sends out Router Advertisement announcements onto the link. These announcements can allow the on-link connected IPv6 nodes to configure themselves with IPv6 address and routing parameters, as specified in RFC2462, without further human intervention. 

3. 

Stateful DHCPv6 The Dynamic Host Configuration Protocol for IPv6 (DHCPv6) has been standardized by the IETF through RFC3315. DHCPv6 enables DHCP servers to pass configuration parameters, 

such as IPv6 network addresses, to IPv6 nodes. It offers the capability of automatic allocation of reusable network addresses and additional configuration flexibility. This protocol is a stateful counterpart to "IPv6 Stateless Address Autoconfiguration" (RFC 2462), and can be used separately, or in addition to the stateless autoconfiguration to obtain configuration parameters. 

4. 

DHCPv6-PD DHCPv6 Prefix Delegation (DHCPv6-PD) is an extension to DHCPv6, and is specified in RFC3633. Classical DHCPv6 is typically focused upon parameter assignment from a DHCPv6 server to an IPv6 host running a DHCPv6 protocol stack. A practical example would be the stateful address assignment of "2001:db8::1" from a DHCPv6 server to a DHCPv6 client. DHCPv6-PD however is aimed at assigning complete subnets and other network and interface parameters from a DHCPv6-PD server to a DHCPv6-PD client. This means that instead of a single address assignment, DHCPv6-PD will assign a set of IPv6 "subnets". An example could be the assignment of "2001:db8::/60" from a DHCPv6-PD server to a DHCPv6-PD client. This will allow the DHCPv6-PD client (often a CPE device) to segment the received address IPv6 address space, and assign it dynamically to its IPv6 enabled.interfaces. 

5.

 Stateless DHCPv6 Stateless DHCPv6 is a combination of "stateless Address Autoconfiguration" and "Dynamic Host Configuration Protocol for IPv6" and is specified by RFC3736. When using stateless-DHCPv6, a device will use Stateless Address Auto-Configuration (SLAAC) to assign one or more IPv6 addresses to an interface, while it utilizes DHCPv6 to receive "additional parameters" which may not be available through SLAAC. For example, additional parameters could include information such as DNS or NTP server addresses, and are provided in a stateless manner by DHCPv6. Using stateless DHCPv6 means that the DHCPv6 server does not need to keep track of any state of assigned IPv6 addresses, and there is no need for state refreshment as result. On network media supporting a large number of hosts associated to a single DHCPv6 server, this could mean a significant reduction in DHCPv6 messages due to the reduced need for address state refreshments. From Cisco IOS 12.4(15)T onwards the client can also receive timing information, in addition to the "additional parameters" through DHCPv6. This timing information provides an indication to a host when it should refresh its DHCPv6 configuration data. This behavior (RFC4242) is particularly useful in unstable environments where changes are likely to occur. 

Answer: C 

Explanation: 

Although OSPF is configured using default classful addressing but OSPF is a link-state routing protocol so it will always send the subnet mask of each network in their advertised routes. Therefore R1 will learn the the complete subnets. Four networks list below will be in the routing table of R1:+ 172.16.2.64/30+ 172.16.2.228/30+ 172.16.2.232/30+ 172.16.3.0/24 Note: Other networks will be learned as “Directly connected” networks (marked with letter “C”) 

Answer: D 

Explanation: 

IPv6 has three types of addresses, which can be categorized by type and scope: 

Unicast addresses. A packet is delivered to one interface. 

Multicast addresses. A packet is delivered to multiple interfaces. 

Anycast addresses. A packet is delivered to the nearest of multiple interfaces (in terms of 

routing distance). 

IPv6 does not use broadcast messages. 

Unicast and anycast addresses in IPv6 have the following scopes (for multicast addresses, 

the scope are built into the address structure): 

Link-local. The scope is the local link (nodes on the same subnet). 

Site-local. The scope is the organization (private site addressing). 

Global. The scope is global (IPv6 Internet addresses). 

In addition, IPv6 has special addresses such as the loopback address. The scope of a 

special address depends on the type of special address. 

Much of the IPv6 address space is unassigned. 

http://technet.microsoft.com/en-us/library/cc757359(v=ws.10).aspx 

Answer: A 

Answer: A 

Explanation: To use IPv6 on your router, you must, at a minimum, enable the protocol and assign IPv6 addresses to your interfaces. 

Answer: B 

Explanation: 

When one route is advertised by more than one routing protocol, the router will choose to use the routing protocol which has lowest Administrative Distance. The Administrative Distances of popular routing protocols are listed below: 

Answer: A 

Explanation: 

Router Switching Function (1.2.1.1)A primary function of a router is to forward packets toward their destination. This is accomplished by using a switching function, which is the process used by a router to accept a packet on one interface and forward it out of another interface. A key responsibility of the switching function is to encapsulate packets in the appropriate data link frame type for the outgoing data link. NOTE In this context, the term “switching” literally means moving packets from source to destination and should not be confused with the function of a Layer 2 switch. After the router has determined the exit interface using the path determination function, the router must encapsulate the packet into the data link frame of the outgoing interface. What does a router do with a packet received from one network and destined for another network? The router performs the following three major steps: 

. Step 1. De-encapsulates the Layer 3 packet by removing the Layer 2 frame header and trailer. . Step 2. Examines the destination IP address of the IP packet to find the best path in the routing table. . Step 3. If the router finds a path to the destination, it encapsulates the Layer 3 packet into a new Layer 2 frame and forwards the frame out the exit interface. 

Answer: B 

Explanation: 

To form an adjacency (become neighbor), router A & B must have the same Hello interval, Dead interval and AREA numbers