Cram Exam Notes 5 Cisco Certified Network Associate CCNA

51.Routing metrics used by IGRP:

Bandwidth, MTU, Reliability, Delay, and Load.

1. Bandwidth: This is represents the maximum throughput of a link.

2. MTU (Maximum Transmission Unit): This is the maximum message length that is acceptable to all links on the path. The larger MTU means faster transmission of packets.

3. Reliability: This is a measurement of reliability of a network link. It is assigned by the administrator or can be calculated by using protocol statistics.

4. Delay: This is affected by the band width and queuing delay.

5. Load: Load is based among many things, CPU usage, packets processed per sec.

52. The metric limit for link-state protocols is 65,533

53. Following are the possible solutions for preventing routing loops.

1. Split Horizon - based on the principle that it is not useful to send the information about a route back in the direction from which the information originally came.

2. Poison Reverse - A router that discovers an inaccessible route sets a table entry consistent state (infinite metric) while the network converges.

3. Hold-down Timers - Hold down timers prevent regular update messages from reinstating a route that has gone bad. Here, if a route fails, the router waits a certain amount of time before accepting any other routing information about that route.

4. Triggered Updates - Normally, new routing tables are sent to neighboring routers at regular intervals (IP RIP every 30 sec / and IPX RIP every 60 sec). A triggered update is an update sent immediately in response to some change in the routing table. Triggered updates along with Hold-down timers can be used effectively to counter routing loops.

54. IP RIP based networks send the complete routing table during update. The default update interval is 30 seconds. IGRP update packet is sent every 90 seconds by default.

55. For IGRP routing, you need to provide the AS (Autonomous System) number in the command. Routers need AS number to exchange routing information. Routers belonging to same AS exchange routing information. OSPF, and IGRP use AS numbers.

56. CDP stands for Cisco Discovery Protocol. This protocol is proprietary of Cisco. CDP runs SNAP (Sub network Access Protocol) at the Data Link Layer. Two Cisco devices running two different Network layer protocol can still communicate and learn about each other.

57. Show IP protocol: This command will show information on RIP timers including routing update timer (30sec default), hold-down timer (default 180sec). It also displays the number of seconds due for next update (this is fraction of update timer). This command also gives the network number for which IP RIP is enabled, Gateway, and the default metric.

1. Show IP route: This command will display the IP routing table entries. In addition, it displays the Gateway of last resort (if one is assigned). It also displays the codes used for various types of routes. Some of the important codes are:

C: directly connected;

S: Statically connected

I : IGRP

R : RIP

2. Show IP interface: This command shows you interface-wise information such as IP address assigned to each interface, whether the interface is up, MTU etc.

3. Debug IP RIP: Debug IP RIP will turn the RIP debugging ON. This will display a continuous list of routing updates as they are sent and received. This leads to lot of overhead, which is the reason that you use "undebug ip rip" to turn-off debugging as soon as you finish with debugging.

58. Cisco router boot configuration commands:

1. boot system - This is a global command that allows you to specify the source of the IOS software image to load. If you configure more than one source, attempts are made to load the IOS from the first command in the configuration to the last successively. If the first fails, the second boot command is used.

2. boot system rom - Loads IOS from ROM.

3. boot system flash - Loads the first file from flash memory.

4. boot system tftp <> - Loads IOS with a filename from a TFTP server.

Cram Exam Notes 4 Cisco Certified Network Associate CCNA

40. There are five different types of passwords:

1. ENABLE PASSWORD - A global command that restricts access to privileged exec mode. This is a non-encrypted password.

2. ENABLE SECRET - Assigns a one-way encryptographic secret password, available in versions 10.3 and up. This secret password is used instead of the enable password when it exists.

3. Virtual Terminal Password (vty password): The virtual terminal password is used for Telnet sessions into the router. The password can be changed at any time. It can be set up when you configure the router from the console. There can be five distinct passwords corresponding to each vty (vty0 to vty4) or there can be a single password for all vtys.

4. Auxiliary Password: Auxiliary password is used to set password to the auxiliary port. This port is used to access a router through a modem.

5. Console Password: Console password is used to set the console port password.

41. Internal memory components of a Cisco router:
. ROM (Read Only Memory); Memory containing micro-code for basic functions to start and maintain the router. ROM is not typically used after the IOS is loaded.

2. RAM/DRAM : stores the running configuration, routing tables, and packet buffers. Some routers, such as the 2500 series, run IOS from Flash, not RAM.

3. NVRAM (Non-Volatile Ram): Memory that does not lose information when power is lost. Stores the system’s configuration file and the configuration register. NVRAM uses a battery to maintain the data when power is turned off.

4. Flash Memory: Stores the compressed IOS (IOS stands for Cisco Internetwork Operating System) image. Flash memory is either EEPROM or PCMCIA card. Flash memory enables you to copy multiple versions of IOS software. This allows you to load a new level of the operating system in every router in your network and then, to upgrade the whole network to that version at an appropriate time.

42. While a packet travels through an Internetwork, it usually involves multiple hops. Note that the logical address (IP address) of source (that created the packet) and destination (final intended destination) remain constant, the hardware (Interface) addresses change with each hop.

43. Default administrative distances some important routing protocols are as below:

Route Source Default Distance

Directly connect Interface 0

Static Route 1

IGRP 100

RIP 120

Unknown 255

An administrative distance of 0 represents highest trustworthiness of the route.

An administrative distance of 255 represents the lowest trustworthiness of the route.

Routed and Routing protocols:

- Routing protocols job is to maintain routing tables and route packets appropriately. Examples of routing protocols are RIP, IGRP, EIGRP, OSPF. Routers can support multiple independent routing protocols and can update and maintain routing tables for each protocol independently.

- Routed protocols are used to transport user traffic from source node to destination node. Examples of routed protocols are IP, IPX, AppleTalk.

44. There are three ways a router learns how to forward a packet:

1. Static Routes - Configured by the administrator manually. The administrator must also update the table manually every time a change to the network takes place. Static routes are commonly used when routing from a network to a stub (a network with a single route) network.

The command is

ip route network mask address/interface [distance]

ex: ip route 165.44.34.0 255.255.255.0 165.44.56.5

Here, 165.44.34.0 is the destination network or subnet

255.255.255.0 is the subnet mask

165.44.56.5 is the default gateway.

2. Default Routes - The default route (gateway of last resort) is used when a route is not known or is infeasible. The command is

ip route 0.0.0.0 0.0.0.0 165.44.56.

The default gateway is set to 165.44.56.5

3. Dynamic Routes - In dynamic routing, the routing tables are automatically updated. Dynamic routing uses broadcasts and multicasts to communicate with other routers.

The commands to enable rip are:

router rip

network .

45. To enable the Cisco IOS to forward packets destined for obscure subnets of directly connected networks onto the best route, you use "ip classless" command.

46. There are broadly three types of routing protocols:

1. Distance Vector (Number of hops) - Distance vector routing determines the direction (vector) and distance to any link in the internetwork. Typically, the smaller the metric, the better the path. EX: Examples of distance vector protocols are RIP and IGRP. Distance vector routing is useful for smaller networks. The limitation is that any route which is greater than 15 hops is considered unreachable. Distance vector protocols listen to second hand information to learn routing tables whereas, Link state protocols build routing tables from first hand information. Routers with distance vector protocols send its entire routing table to each of its adjacent neighbors.

2. Link State Routing: Link State algorithms are also known as Shortest Path First (SPF) algorithms. SPF generates the exact topology of the entire network for route computation, by listening to the first hand information. Link State protocols take bandwidth into account using a cost metric. Link State protocols only send updates when a change occurs, which makes them more efficient for larger networks. Bandwidth and delay are the most widely used metrics when using Link-State protocols. EX: OSPF and NLSP.

Benefits of Link State protocols:

1. Allows for a larger scalable network

2. Reduces convergence time

3. Allows “supernetting”

3. Balanced Hybrid - Balanced Hybrid combines some aspects of Link State and Distance Vector routing protocols. Balanced Hybrid uses distance vectors with more accurate metrics to determine the best paths to destination networks. EX: EIGRP.

47. Distance vector protocol depends only on Hop count to determine the nearest next hop for forwarding a packet. One obvious disadvantage is that, if you have a destination connected through two hops via T1 lines, and if the same destination is also connected through a single hop through a 64KBPS line, RIP assumes that the link through 64KBPS is the best path!

48. RIP (and IGRP) always summarizes routing information by major network numbers. This is called classfull routing.

49. Convergence is the term used to describe the state at which all the internetworking devices, running any specific routing protocol, are having identical information about the internetwork in their routing tables. The time it takes to arrive at identical information of the internetwork is called Convergence Time.

50. RIP,RIP2, and IGRP use distance vector algorithms.

RIP2 transmits the subnet mask with each route. This feature allows VLSM (Variable Length Subnet Masks) by passing the mask along with each route so that the subnet is

Cram Exam Notes 3 Cisco Certified Network Associate CCNA

31. Ethernet_II has a type field to identify the upper-layer protocol. 802.3 has only a length field and can't identify the upper-layer protocol.

32.To find valid hosts given an IP address (say 156.16.3.52) and a subnet mask (sat a 12-bit subnet). The valid hosts are determined as below:

A 12-bit subnet mask gives us 255.255.255.240; 4094 subnets, each with 14 hosts. (Host addresses of all zeros and all 1s can't be assigned). The 156.16.3.52 is in the 48 subnet range. The valid range is through 49 - 62. 63 is a broadcast address.

Here is how you get the subnet range:

1. Find the subnet mask. In this case, default subnet mask for Class B address is 255.255.0.0. There are additional; 12 bits in the subnet mask. Now the subnet mask looks like:

11111111.11111111.11111111.11110000. This is equal to 255.255.255.240.0.

2. Now, deduct the lowest value octet (Which is non zero), from 256. Here, (256-240)=16.

This is the value that the subnets are incremented. Therefore, you will have hosts with values from:

156.16.3.1 to 156.16.3.14 (All 0s and all 1s host addresses can not be used)

156.16.3.17 to 156.16.3.30

156.16.3.33 to 156.16.3.46

156.16.3.49 to 156.16.3.62 and so on.

It is important to know that subnets are incrementing here by a factor of 16.

33. The following are some important commands that can be used to edit and review command history buffer on a Cisco router. It will be useful to practice these commands.

A : Move to the beginning of the command line

E : Move to the end of the command line

F : Move forward one character, same as using "Right Arrow".

B : Move backward one character, same as using "Left Arrow".

P : Repeat Previous command, same as using "Up Arrow".

N : Repeat Next (more recent) command, same as using "Down Arrow".

B : Moves to beginning of previous word.

F : Moves to beginning of next word.

R : Creates new command prompt, followed by all the characters typed at the last one.

34. The following are some frequently used COPY commands:

1. COPY RUNNING-CONFIGURATION STARTUP-CONFIGURATION (alternatively, you can use an older version of the command, WRITE MEMORY): This command saves the current configuration to NVRAM. Alternatively, we can issue the command using short form: COPY RUNNING STARTUP - Copies configuration from RAM to NVRAM
2. COPY STARTUP RUNNING - This command merges configuration from NVRAM to RAM.
3. COPY FLASH TFTP - Copies current IOS from router flash memory to TFTP server.
4. COPY TFTP FLASH - Copies image file from TFTP server to flash. This is used to upgrade the IOS image file to a newer version, or if your IOS image becomes corrupt.

35. The banner is displayed whenever anyone logs in to your Cisco router. The syntax is

- "banner motd # " . MOTD stands for "Message Of The Day".

# symbol signifies the start of the banner message to the router. You will be prompted for the message to be displayed. You need to enter "#" symbol at the end of the message, signifying that the message has ended.

36. Router modes of operation:

1. User EXEC mode (Prompt: Router>):- This is the LOWEST level of access. This allows examination of router status, see routing tables, and do some diagnostics. However, you cannot change the router configuration, view the configuration files, or control the router in any way. The prompt in this mode is "Router>".

2. Privileged (enable) EXEC mode (Prompt: Router#):- This mode allows you to have all the privileges of EXEC (user) mode plus commands that enable you to view configuration files, change the router configuration, perform troubleshooting that could potentially disrupt traffic. The default prompt for this mode is "Router#".When you are working in the privileged mode (at # prompt), you can get back to user mode by typing "disable" at the "#" prompt.

3. Global Configuration mode (Prompt: Router (Config)#):-

Global configuration mode allows you to perform tasks that affect the entire router, such as naming the router, configuration of banner messages, enabling routed protocols, and generally anything that affects the operation of the entire router.

When you first switch on a router, you enter Setup mode. Setup mode is different from configuration mode in that setup mode appears when there is no configuration file present. Upon entering setup mode, you can supply some basic configuration parameters to Cisco router.

37. You can use "tab" to complete the command that you are typing.

38. SHOW command is extensively used for seeing the status and configuration information of the router.

Some of the frequently used commands are:

1. SHOW RUNNING-CONFIGURATION -This command displays the router's active configuration file, passwords, system name, and interface settings, interfaces IP addresses etc.

2. SHOW INTERFACE - Shows status and configuration information of the local interfaces. The first line says something like “TokenRing1 is up, line protocol is up”. The first part “TokenRing1 is up” describes the physical layer components such as electrical cabling and signaling are OK. The second part “line protocol is up” means that the router is detecting keep-alive messages. The router may be put into administratively down status, at which point the line would read, “TokenRing1 is administratively down, line protocol is down.”

3. SHOW INTERFACE SERIAL 0 - Shows the serial 0 configuration.

4. SHOW INTERFACES - Displays statistics for all interfaces configured on the switch.

5. SHOW PROCESS - Displays a router’s CPU utilization.

6. SHOW CONFIG - Displays information on the startup configuration.

7. SHOW VERSION - Displays information about the system hardware (RAM/ROM), software version, names of configuration files, and boot-images. This command will also show the current configuration register value.

39. The Cisco router can be configured from many locations.

1. Console port: During the initial installation, you configure the router from a console terminal connected to the "Console port" of the router.

2. Virtual Terminals (vty): A virtual terminal (vty) is typically accessed through Telnet. A router can be accessed through vty after it the initial installation in the network. There are five virtual terminals, namely, vty0,vty1,vty2,vty3,vty4.

3. Auxiliary Port: you can configure a router through auxiliary port. Typically, a modem is used to configure the modem through aux port.

4. TFTP Server: Configuration information can be downloaded from a TFTP server over the network.

5. NMS (Network Management Station): You can also manage router configuration through NMS such as CiscoWorks or HP OpenView.

40. There are five different types of passwords:

1. ENABLE PASSWORD - A global command that restricts access to privileged exec mode. This is a non-encrypted password.

2. ENABLE SECRET - Assigns a one-way encryptographic secret password, available in versions 10.3 and up. This secret password is used instead of the enable password when it exists.

3. Virtual Terminal Password (vty password): The virtual terminal password is used for Telnet sessions into the router. The password can be changed at any time. It can be set up when you configure the router from the console. There can be five distinct passwords corresponding to each vty (vty0 to vty4) or there can be a single password for all vtys.

4. Auxiliary Password: Auxiliary password is used to set password to the auxiliary port. This port is used to access a router through a modem.

5. Console Password: Console password is used to set the console port password.

Cram Exam Notes 2 Cisco Certified Network Associate CCNA

12. Telnet, FTP, and TFTP:

1. Telnet is used for terminal emulation that runs programs remotely. Telnet uses TCP/IP protocol.

2. Telnet requires a username and password to access.

3. FTP (File Transfer Protocol) is a connection oriented protocol. It uses TCP/IP for file transfer. Compare this with TFTP (Trivial File Transfer Protocol) that uses UDP (Connectionless protocol). SNMP uses UDP over IP. Tracert, Ping use ICMP as their base protocol. FTP is used to transfer files.

13. Maximum hop count supported by RIP is 15.

14. The port numbers used by different programs are as below:

I. FTP : Port #21

II. Telnet: Port #23

III. SMTP: Port #25

IV. SNMP: Port #161

It is important to know that FTP, Telnet, SMTP use TCP; whereas TFTP, SNMP use UDP.

15. SNMP is part of TCP/IP protocol suite. It allows you to monitor and manage a network from a centralized place by using SNMP Manager software. The systems or devices that provide the responses are called agents (or MIBs). An SNMP agent is any computer running SNMP agent software.

MIB stands for Management Information Base. It is part of SNMP agent database. A MIB records and stores information abut the host it is running on. An SNMP manager can request and collect information from an agent's MIB. Routers are typical MIB agents. SNMP agent generates "trap" messages that are then sent to an SNMP management console, which is a trap destination.

17. Address Resolution Protocol (ARP) is used to resolve or map a known IP address to a MAC sub layer address to allow communication on a multi-access medium such as Ethernet. Reverse ARP (RARP) is used to obtain an IP address using an RARP broadcast. RARP can be used to boot diskless workstations over a network.

18. The 7 layers of OSI model are:

1. The Application Layer: Application layer is responsible for identifying and establishing the availability of desired communication partner and verifying sufficient resources exist for communication. Some of the important application layer protocols are: WWW, SMTP, FTP, etc.

2. The Presentation Layer: This layer is responsible for presenting the data in standard formats. This layer is responsible for data compression, decompression, encryption, and decryption. Some Presentation Layer standards are: JPEG, MPEG, MIDI, PICT, Quick Time, TIFF.

3. The Session Layer: Session Layer is responsible for co-ordinating communication between systems/nodes. The following are some of the session layer protocols and interfaces: a) Network File System (NFS), SQL, RPC (Remote Procedure Call), X-Windows, ASP, DNA SCP.

4. The Transport Layer: The Transport Layer is responsible for multiplexing upper-layer applications, session establishment, and tearing-down of virtual circuits. This layer is responsible for flow control, to maintain data integrity.

5. The Network Layer: There can be several paths to send a packet from a given source to a destination. The primary responsibility of Network layer is to send packets from the source network to the destination network using a pre-determined routing methods. Routers work at Network layer.

6. The Data Link Layer:

Data Link Layer is layer 2 of OSI reference model. This layer is divided into two sub-layers:

A. Logical Link Control (LLC) sub-layer.

B. Media Access Control (MAC) sub-layer.

The LLC sub-layer handles error control, flow control, framing, and MAC sub-layer addressing.

The MAC sub-layer is the lower of the two sub-layers of the Data Link layer. MAC sub-layer handles access to shared media, such a Token passing or Ethernet.

7. Physical Layer: The actual flow of signals take place through Physical layer. At Physical layer, the interface between the DTE and DCE is determined. The following are some of the standard interfaces are defined at Physical layer: EIA/TIA-232, EIA/TIA-449,V.24,V.35,X.21,G.703,HSSI (High Speed Serial Interface).

19. Repeaters, Bridges, and Routers:

I. Repeaters work at Physical layer (Layer 1),

II. Bridges and simple switches work at Data Link Layer (Layer 2),

III. Routers work at Network Layer (Layer 3) of ISO Reference Model. 20. CSU / DSU is an acronym for Channel Service Unit / Data Service Unit. CSU/DSU is part of Customer Premise Equipment (CPE). CSU / DSU connect to a Central Office (CO), a telephone switching company located nearer to the customer.

Cram Exam Notes Cisco Certified Network Associate CCNA

About CCNA Exam: CCNA Certification is offered by Cisco®. CCNA tests your knowledge and skills in the areas of simple LAN/WAN switching, Cisco IOS, and routing technologies. Topics include TCP/IP model of internetworking, configuring, and troubleshooting RIP, RIP v2, IGRP, EIGRP, OSPF, NAT, Remote Access using some of the most widely used Cisco switches and routers. Please visit the Cisco website for current objectives. Two recommended resources for Cisco certification preparation are Cisco Press "Cisco CCNA Preparation Library" and CCNA by Sybex. There are many others that are very good, but not widely known. CCNA is the foundation exam for CCNP (Cisco Certified Networking Professional). The exam notes is a brief review of important points that help in quick review of key points.

Cram Notes:
1. Internetwork IP addressing:

IP addresses are written using decimal numbers separated by decimal points. This is called dotted decimal notation of expressing IP addresses.

The different classes of IP addresses is as below:

Class	Format	Leading Bit pattern	Network address Range	Maximum networks	Maximum hosts/ nodes
A	N.H.H.H	0	0-126	127	16,777,214
B	N.N.H.H	10	128-191	16,384	65,534
C	N.N.N.H	110	192-223	2,097,152	254

- Network address of all zeros means "This network or segment".

- Network address of all 1s means " all networks", same as hexadecimal of all Fs.

- Network number 127 is reserved for loop-back tests.

- Host (Node) address of all zeros mean "This Host (Node)".

- Host (Node) address of all 1s mean "all Hosts (Nodes) " on the specified network.

2. The range of numbers from 224.0.0.0 to 239.255.255.255 are used for multicast packets. This is known as Class D address range.
3. Subnetting is nothing but creating networks within a network. Subnetting allows an organization with a single IP address (Class A /ClassB /ClassC) to have multiple subnetworks, thus allowing several physical networks within the organization.

4. How to maximize the number of subnets for a given number of hosts:

Let us take a network ID of 168.8.0.0, and find the maximum number of possible subnets and the corresponding subnet mask that can accommodate at least 500 hosts. The steps involved are outlined below:

I. Find the Class of the IP address, in this case it is a class B network. Class B network has the form N.N.H.H. Therefore, we have a total of 16 bits (two octets) for assigning to internal networks and hosts. The minimum number of host addresses required is 500. The last octet corresponds to 2^8 = 256 hosts which is still less than 500 Hosts.. Therefore, you have to borrow one more bit from the third octet to make it 256*2 = 512 Hosts. This leaves 7 bits in the third octet for assigning subnet addresses. This is equal to 2^7=128 subnets.

II. Write the 7 bits available for subnetting in third octet in the form 11111110 (last bit being the Host bit). The decimal equivalent of the first seven bits is 2^7+2^6+2^5+2^4+2^3+2^2+2^1

= 128 + 64 +32 + 16 + 8 + 4 + 2 = 254.

III. Therefore, the subnet mask required is 255.255.254.0.

6. How to maximize the number of hosts for a given number of subnets:

Determining the subnet mask that allows maximum number of hosts:

Let us consider an IP address 196.202.56.0 with four subnets and maximize the number of host for the given subnets. The steps involved are as below:

I. The number of subnets required are four. We need to add subnets of all ones and all zeros to this. This is because all zeros and all ones subnets belong to "this subnet" and "all subnets" broadcasts and can not be used. Therefore, the total number of subnets to be reserved is 4+2 = 6.

II. We want to implement maximum possible Hosts. Therefore, we need to minimize the number of subnets. This minimum number is 6 here. If we reserve 2 bits, it results in only 2^2=4 subnets which is less than 6. Therefore, we have to reserve 3 bits for implementing subnets, resulting in 2^3=8 subnets. This is now optimized for maximum number of Hosts (as we have optimized for minimum number of subnets).

III. Write the 3 bits available for subnetting in fourth octet in the form 11100000 (Five 0s being Host bits). The decimal equivalent is 2^7+2^6+2^5

= 128 + 64 +32 = 224.

IV. Therefore, the subnet mask required is 255.255.255.224.

7. 127.0.0.1 is the local loop back address.

8. In an internetwork, the number of distinct IPs' required are

1. One each per client computer

2. One each per server computer

3. One each per router interface.

For example, your network has 2 servers, 26 clients machines, and 2 router interfaces the total number of IP addresses required are 30.

9. Finding the number of Hosts and subnets available for a given subnet mask: For example, let us find the number of hosts and subnets available for an IP 156.233.42.56 with a subnet mask of 7 bits.

a. Class B network has the form N.N.H.H, the default subnet mask is 16 bits long. There is additional subnet mask of 7 bits long.

b. 7 bits of subnet mask corresponds to (2^7-2)=128-2 = 126 subnets.

c. 9 bits (16-7) of host addresses corresponds to (2^9-2)=512-2 = 510 hosts.

Some times, the subnet mask is specified with the bits available in the default subnet mask. In this case the bits available in default subnet mask is 16. Therefore, total number of bits available in the subnet mask are 16+7=23. If you are given a subnet mask of 23 bits long for a class B address, it is understood that it contains the bits from the default subnet mask as well.

Hence, 126 subnets and 510 hosts are available. 10. The directed broadcast should reach all Hosts on the intended network (or subnet, if sub netted). For example, the directed broadcast address for an IP network 196.233.24.15 with default subnet mask is 196.233.24.255. This is arrived by putting all 1s for the host potion of the IP address.

Final CCNA 4 (H)

1. Which encapsulation protocol when deployed on a Cisco router over a serial interface is only compatible with another Cisco router?

PPP
SLIP
xxxHDLC
Frame Relay

2. What is a characteristic feature of a worm?

xxxexploits a known vulnerability
attaches to executable programs
masquerades as a legitmate program
lies dormant until triggered by an event, time, or date

3.An administrator is configuring a dual stack router with IPv6 and IPv4 using RIPng. The administrator receives an error message when trying to enter the IPv4 routes into RIPng. What is the cause of the problem?

When IPv4 and IPv6 are configured on the same interface, all IPv4 addresses are over-written in favor of the newer technology.
Incorrect IPv4 addresses are entered on the router interfaces.
RIPng is incompatible with dual-stack technology.
xxxIPv4 is incompatible with RIPng

4.Which statement accurately describes a characteristic of a security policy?

xxxIt creates a basis for legal action if necessary.
It should not need altering once it is implemented.
It provides step-by-step procedures to harden routers and other network devices.
It is kept private from users to prevent the possibility of circumvention of security measures

5. Which characteristic of VPN technology prevents the contents of data communications from being read by unauthorized parties?

QoS
latency
reliability
xxxconfidentiality

6. Refer to the exhibit. A network administrator is configuring Frame Relay on router HQ. It is desired that each Frame Relay PVC between the routers be in a separate subnet. Which two commands on HQ will accomplish this task for the connection to R1? (Choose two.)

HQ(config)# interface S0/0/0
HQ(config)# interface S0/0/0.1 multipoint
xxxHQ(config)# interface S0/0/0.1 point-to-point
HQ(config-subif)# frame-relay interface dlci 103
HQ(config-subif)# frame-relay interface dlci 301
xxxHQ(config-if)# frame-relay map ip 172.16.1.1 255.255.255.0 301 broadcast

7. Refer to the exhibit. Router1 and Router2 are directly connected over a point-to-point serial link. Router1 initiates a PPP session with Router2. Which statement is true based on the configuration?

The password is sent in clear text.
The routers are unable to authenticate.
The username and password are sent encrypted.
xxxA hash value of the username and password are sent.

8. A technician has been asked to run Cisco SDM one-step lockdown on the router of a customer. What will be the result of this process?

Traffic is only forwarded from SDM-trusted Cisco routers.
Security testing is performed and the results are saved as a text file stored in NVRAM.
xxxThe router is tested for potential security problems and any necessary changes are made.
All traffic entering the router is quarantined and checked for viruses before being forwarded.

9. Which two statements are true about creating and applying access lists? (Choose two.)

xxxThere is an implicit deny at the end of all access lists.
xxxOne access list per port, per protocol, per direction is permitted.
Access list entries should filter in the order from general to specific.
The term "inbound" refers to traffic that enters the network from the router interface where the ACL is applied.
Standard ACLs should be applied closest to the source while extended ACLs should be applied closest to the destination.

10. Refer to the exhibit. Company ABC expanded its business and recently opened a new branch office in another country. IPv6 addresses have been used for the company network. The data servers Server1 and Server2 run applications which require end-to-end functionality, with unmodified packets that are forwarded from the source to the destination. The edge routers R1 and R2 support dual stack configuration. What solution should be deployed at the edge of the company network in order to successfully interconnect both offices?

a new WAN service supporting only IPv6
NAT overload to map inside IPv6 addresses to outside IPv4 address
xxxa manually configured IPv6 tunnel between the edge routers R1 and R2
static NAT to map inside IPv6 addresses of the servers to an outside IPv4 address and dynamic NAT for the rest of the inside IPv6 addresses

11. A company uses a PVC with a committed information rate (CIR) of 128 kb/s and a committed burst information rate (CBIR) of 64 kb/s. The link is used to periodically send updates at a rate of 144 kb/s. What will happen to the update traffic?

The traffic will be sent, but the company will be charged a penalty.
The traffic will be sent using the additional CBIR and will be guaranteed delivery.
xxxThe traffic will be dropped at the CO for exceeding the committed information rate.
The traffic will be sent, but the burst traffic will be marked for discard if congestion is encountered.

12. Refer to the exhibit. All devices are configured as shown in the exhibit. PC1 is unable to ping the default gateway. What is the cause of the problem?

The default gateway is in the wrong subnet.
STP has blocked the port that PC1 is connected to.
xxxPort Fa0/2 on S2 is assigned to the wrong VLAN.
S2 has the wrong IP address assigned to the VLAN30 interface.

13. A system administrator must provide Internet connectivity for ten hosts in a small remote office. The ISP has assigned two public IP addresses to this remote office. How can the system administrator configure the router to provide Internet access to all ten users at the same time?

Configure DHCP and static NAT.
Configure dynamic NAT for ten users.
Configure static NAT for all ten users.
xxxConfigure dynamic NAT with overload.

14. Refer to the exhibit. From the output of the show interfaces and ping commands, at which layer of the OSI model is a fault indicated?

application
transport
xxxnetwork
data link
physical

15. Refer to the exhibit. Results of the show vlan and show vtp status commands for switches S1 and S2 are displayed in the exhibit. VLAN 11 was created on S1. Why is VLAN 11 missing from S2?

There is a Layer 2 loop.
xxxThe VTP domain names do not match.
Only one switch can be in server mode.
S2 has a higher spanning-tree priority for VLAN 11 than S1 does.

16. Refer to the exhibit. What is the effect of the extended ACL when applied inbound on the S0/0/0 interface on R2?

All IP traffic will be permitted during the specified days and time range.
Both IP and Telnet traffic will be permitted during the specified days and time range.
Only Telnet traffic destined for 172.16.10.0/24 will be permitted during the specified days and time range.
xxxTelnet traffic will be permitted only during the specified days and time range. All other network traffic will be permitted any time.

17. Which three guidelines would help contribute to creating a strong password policy? (Choose three.)

Once a good password is created, do not change it.
xxxDeliberately misspell words when creating passwords.
xxxCreate passwords that are at least 8 characters in length.
xxxUse combinations of upper case, lower case, and special characters.
Write passwords in locations that can be easily retrieved to avoid being locked out.
Use long words found in the dictionary to make passwords that are easy to remember.

18. Refer to the exhibit. How is the TCP/IP configuration information specified by the default-router and dns-server commands made available?



The TCP/IP information is forwarded to a 10.0.1.3 to be supplied to DHCP clients.
The TCP/IP information is used by DNS clients to forward all data to the default gateway on R1 of 10.0.1.3.
The TCP/IP information is supplied to any DHCP client on the network connected to the FastEthernet 0/0 interface of R1.
The TCP/IP information is applied to each packet that enters R1 through the FastEthernet 0/0 interface that are hosts on the 10.0.1.0 /24 network except packets from addresses 10.0.1.2, 10.0.1.16, and 10.0.1.254.

19. Which variable is permitted or denied by a standard access control list?

protocol type
xxxsource IP address
source MAC address
destination IP address
destination MAC address

20. When configuring a Frame Relay connection, what is the purpose of Inverse ARP?

to assign a DLCI to a remote peer
to disable peer requests from determining local Layer 3 addresses
to negotiate LMI encapsulations between local and remote Frame Relay peers
xxxto create a mapping of DLCI to Layer 3 addresses that belong to remote peers

21. An issue of response time has recently arisen on an application server. The new release of a software package has also been installed on the server. The configuration of the network has changed recently. To identify the problem, individuals from both teams responsible for the recent changes begin to investigate the source of the problem. Which statement applies to this situation?

Scheduling will be easy if the network and software teams work independently.
xxxIt will be difficult to isolate the problem if two teams are implementing changes independently.
Results from changes will be easier to reconcile and document if each team works in isolation.
Only results from the software package should be tested as the network is designed to accommodate the proposed software platform.

22. What is the result when the command permit tcp 10.25.132.0 0.0.0.255 any eq smtp is added to a named access control list and applied on the inbound interface of a router?

TCP traffic with a destination to the 10.25.132.0/24 is permitted.
Only Telnet traffic is permitted to the 10.24.132.0/24 network
Ttraffic from 10.25.132.0/24 is permitted to anywhere on using any port.
xxxTraffic using port 25 from the 10.25.132.0/24 is permitted to all destinations.

23. At what point in the PPP connection process does the authentication phase occur?

after NCP establishes Layer 3 parameters
xxxbefore LCP begins the link establishment process
after the initial Configure-Request message from the link initiator
after the link initiator receives a Configure-Ack message from the responder

24. An administrator is unable to receive e-mail. While troubleshooting the problem, the administrator is able to ping the local mail server IP address successfully from a remote network and can successfully resolve the mail server name to an IP address via the use of the nslookup command. At what OSI layer is the problem most likely to be found?

physical layer
data link layer
network layer
xxxapplication layer

25. Refer to the exhibit. Which statement is true about the Frame Relay connection?

The Frame Relay connection is in the process of negotiation.
xxxA congestion control mechanism is enabled on the Frame Relay connection.
The “ACTIVE” status of the Frame Relay connection indicates that the network is experiencing congestion.
Only control FECN and BECN bits are sent over the Frame Relay connection. No data traffic traverses the link.

26. A light manufacturing company wishes to replace its DSL service with a non-line-of-sight broadband wireless solution that offers comparable speeds. Which solution should the customer choose?

Wi-Fi
satellite
xxxWiMAX
Metro Ethernet

27. Refer to the exhibit. This router is being configured to use SDM, but the SDM interface of the router cannot be accessed. What is the cause of the problem?

xxxThe VTY lines are not configured correctly.
The HTTP timeout policy is not configured correctly.
The authentication method is not configured correctly.
The username and password are not configured correctly.

28. Which option correctly defines the capacity through the local loop guaranteed to a customer by the service provider?

BE
DE
xxxCIR
CBIR

29.Refer to the exhibit. What is placed in the address field in the header of a frame that will travel from the DC router to the Orlando router?

DLCI 123
xxxDLCI 321
10.10.10.25
10.10.10.26
MAC address of the Orlando router

30. Where does a service provider assume responsibility from a customer for a WAN connection?

local loop
DTE cable on router
xxxdemarcation point
demilitarized zone

31. A company is looking for a WAN solution to connect its headquarters site to four remote sites. What are two advantages that dedicated leased lines provide compared to a shared Frame Relay solution? (Choose two.)

xxxreduced jitter
reduced costs
xxxreduced latency
the ability to burst above guaranteed bandwidth
the ability to borrow unused bandwidth from the leased lines of other customers

32. Refer to the exhibit. A host connected to Fa0/0 is unable to acquire an IP address from the DHCP server. The output of the debug ip dhcp server command shows "DHCPD: there is no address pool for 192.168.3.17". What is the problem?

The address 192.168.3.17 address is already in use by Fa0/0.
xxxThe pool of addresses for the 192Network pool is configured incorrectly.
The ip helper-address command should be used on the Fa0/0 interface.
The 192.168.3.17 address has not been excluded from the 192Network pool.

33.A network administrator is tasked with maintaining two remote locations in the same city. Both locations use the same service provider and have the same service plan for DSL service. When comparing download rates, it is noticed that the location on the East side of town has a faster download rate than the location on the West side of town. How can this be explained?

The West side has a high volume of POTS traffic.
The West side of town is downloading larger packets.
xxxThe service provider is closer to the location on the East side.
More clients share a connection to the DSLAM on the West side.

34. Which data link layer encapsulation protocol is used by default for serial connections between two Cisco routers?

ATM
Frame Relay
xxxHDLC
PPP
SDLC

35. Which additional functionality is available on an interface when the encapsulation is changed from HDLC to PPP?

flow control
error control
xxxauthentication
synchronous communication

36. When NAT is in use, what is used to determine the addresses that can be translated on a Cisco router?

access control list
routing protocol
inbound interface
ARP cache

37. Refer to the exhibit. What statement is true about the core router devices?

They use multiport internetworking devices to switch traffic such as Frame Relay, ATM, or X.25 over the WAN.
They provide internetworking and WAN access interface ports that are used to connect to the service provider network.
They provide termination for the digital signal and ensure connection integrity through error correction and line monitoring.
xxxThey support multiple telecommunications interfaces of the highest speed and are able to forward IP packets at full speed on all of those interfaces.

38. Refer to the exhibit. A network administrator has issued the commands that are shown on Router1 and Router2. A later review of the routing tables reveals that neither router is learning the LAN network of the neighbor router. What is most likely the problem with the RIPng configuration?

The serial interfaces are in different subnets.
xxxThe RIPng process is not enabled on interfaces.
The RIPng processes do not match between Router1 and Router2.
The RIPng network command is missing from the IPv6 RIP configuration.

39. Which two protocols in combination should be used to establish a link with secure authentication between a Cisco and a non-Cisco router? (Choose two.)

HDLC
xxxPPP
xxxSLIP
PAP
CHAP

40. Refer to the exhibit. This serial interface is not functioning correctly. Based on the output shown, what is the most likely cause?

improper LMI type
interface reset
PPP negotiation failure
unplugged cable

41. Which statement is true about NCP?

Link termination is the responsibility of NCP.
xxxEach network protocol has a corresponding NCP.
NCP establishes the initial link between PPP devices.
NCP tests the link to ensure that the link quality is sufficient.

42. Refer to the exhibit. Which statement correctly describes how Router1 processes an FTP request packet that enters interface S0/0/0, and is destined for an FTP server at IP address 172.16.1.5?

The router matches the incoming packet to the statement that is created by access-list 201 permit ip any any command and allows the packet into the router.
The router reaches the end of ACL 101 without matching a condition and drops the packet because there is no statement that was created by access-list 101 permit ip any any command.
xxxThe router matches the incoming packet to the statement that was created by the access-list 101 permit ip any 172.16.1.0 0.0.0.255 command, ignores the remaining statements in ACL 101, and allows the packet into the router.
The router matches the incoming packet to the statement that was created by the access-list 201 deny icmp 172.16.1.0 0.0.0.255 any command, continues comparing the packet to the remaining statements in ACL 201 to ensure that no subsequent statements allow FTP, and then the router drops the packet.

43. Refer to the exhibit. RIPv2 has been configured on all routers in the network. Routers R1 and R3 have not received any RIP routing updates. What will fix the issue?

xxxEnable RIP authentication on R2.
Issue the ip directed-broadcast command on R2.
Change the subnet masks to 10.11.12.0/8 and 172.16.40.0/16 on R2.
Enable CDP on R2 so that the other routers will receive routing updates

44. Refer to the exhibit. What happens if the network administrator issues the commands shown when an ACL called Managers already exists on the router?

The commands overwrite the existing Managers ACL.
xxxThe commands are added at the end of the existing Managers ACL.
The network administrator receives an error stating that the ACL already exists.
The commands will create a duplicate Managers ACL containing only the new commands being entered.

45. Which security solution has the responsibility of monitoring suspicious processes that are running on a host and that might indicate infection of Trojan horse applications?

xxxantivirus application
operating system patches
intrusion prevention system
Cisco Adaptive Security Appliance

46. Which statement is true about wildcard masks?

A wildcard mask must be created by inverting the subnet mask.
A wildcard mask performs the same function as a subnet mask.
xxxA wildcard mask of 0.0.0.0 means the address should match exactly.
A wildcard mask uses a "1" to identify IP address bits that must be checked.

47. Refer to the exhibit. A network administrator is trying to backup the IOS software on R1 to the TFTP server. He receives the error message that is shown in the exhibit, and cannot ping the TFTP server from R1. What is an action that can help to isolate this problem?

Use correct source file name in the command.
Verify that the TFTP server software is running.
Make sure that there is enough room on the TFTP server for the backup.
xxxCheck that R1 has a route to the network where the TFTP server resides.

48. Refer to the exhibit. A network administrator is creating a prototype to verify the new WAN design. However, the communication between the two routers cannot be established. Based on the output of the commands, what can be done to solve the problem?

Replace the serial cable .
Replace the WIC on RA.
xxxConfigure RA with a clock rate command.
Issue a no shutdown interface command on RB.

49. Refer to the exhibit. From the output of the show interface commands, at which OSI layer is a fault indicated?

application
transport
network
xxxdata link
physical

50. Which type of ACL will permit traffic inbound into a private network only if an outbound session has already been established between the source and destination?

extended
xxxreflexive
standard
time-based

51. Which IEEE 802.16 broadband wireless technology allows users to connect to the ISP at speeds comparable to DSL and cable?

Wi-Fi
satellite
xxxWiMAX
Metro Ethernet

52. Which option represents a best practice for applying ACLs?

Named ACLs are less efficient than numbered ACLs.
Standard ACLs should be applied inside the core layer.
ACLs applied to outbound interfaces use fewer router resources.
xxxExtended ACLs should be applied closest to the source that is specified by the ACL.