CCNA Flash

Which router command allows you to view the entire contents of all access lists?

To see the contents of all access lists, use the show access-lists command. See Chapter 10

Which protocol does DHCP use at the Transport layer?

User Datagram Protocol is a connection network service at the Transport layer, and DHCP uses this connectionless service. See Chapter 2

What does a VLAN do?

VLANs break up broadcast domains at Layer 2. Chapter 9

What protocols are used to configure trunking on a switch?

VTP is not right because it has nothing to do with trunking except that it sends VLAN information across a trunk link. 802.1Q and ISL are used to configure trunking on a port. See Chapter 9

What flavor of Network Address Translation can be used to have one IP address allow many users to connect to the global Internet?

Port Address Translation allows a one-to-many approach to network address translation. Chapter 11

What are two main types of access control lists (ACLs)?

Standard and extended access control lists (ACLs) are used to configure security on a router.

What is a stub network?

Stub networks have only one connection to an internetwork. Only default routes can be set on a stub network loops may occur. See Chapter 7

Which one of the following is true regarding VLANs?

Switches do not propagate VLAN information by default; you must configure the VTP domain. VLAN Trunking Protocol is used to propagate VLAN information across a trunk link. See Chapter 9

Which command is used to upgrade an IOS on a Cisco router?

The copy tftp flash comman places a new files in flash memory, which is the default location for the Cisco IOS in Cisco routers. See Chapter 5

Which of the following is the valid host range for the subnet on which the IP address 192.168.168.188 255.255.255.192 resides?

256-192=64. 64+64=128. 128+64=192. The subnet is 128, the broadcast address is 191, and the valid host range is the numbers in between, or 129-190. See Chapter 3

How long is an IPv6 address

An IPv6 is 128 bits long, compared to an IPv4 address, which is only 32 bits long. Chapter 13

How many broadcast domains are created when you segment a network with a 12-port switch?

By default, switches break up collision domains but are one large broadcast domain. See Chapter 1

Which class of IP address has the most host addresses available by default?

Class A addressing provides 24 bits for host addressing. See chapter 3.

What command is used to create a backup configuration?

The command to back up the configuration on a router is copy running-config startup-config. See Chapter 5

You have 10 users plugged into a hub running 10Mbps half-duplex. There is a server connected to the switch running 10 MBps half-duplex as well. How much bandwidth does each host have to the server?

Each device has 10 MBps to the server. Chapter 8

How often are BPDUs sent from a layer 2 device?

Every 2 seconds, BPDUs are sent out from all active bridge ports by default. See Chapter 7.

Where is a hub specified in the OSI model?

Hubs regenerate electrical signals, which are specified at the Physical layer. See Chapter 1

Which protocol is used to send a destination network unknown message back to originating hosts?

ICMP is the protocol at the Network later that is used to send messages back to an originating router. Chapter 2.

Which protocol does Ping use?

ICMP is the protocol at the Network layer that is used to send echo requests and replies. See Chapter 2

Which WLAN IEEE specification allows up to 54Mbps at 2.4 GHz?

IEEE 802.11B is 2.4GHZ, but with a maximum of only 11 Mbps. IEEE 802.11G is in the 2.4GHz range, with a top speed of 54Mbps. See chapter 12

How many collision domains are created when you segment a network with a 12-port switch?

Layer 2 switching creates individual collision domains. See chapter 1.

What protocol provides dynamic addressing, authentication, and multilink?

Link Control Protocol in the PPP stack provides dynamic addressing, authentication, and multilink.

What protocol does PPP use to identify the Network layer protocol?

Network Control Protocol is uses to identify the Network layer protocol used in the packet. Chapter 14

If your router is facilitating a CSU/DSU, which of the following commands do you need to use to provide the router with a 64000bps serial link?

The clock rate comand is two words, and the speed of the line is in bps. See Chapter 4

To back up an IOS, what command will you use?

The command copy flash tftp will prompt you to back up an existing IOS in flash to a TFTP host. See Chapter 5

if you wanted to delete configuration stored in NVRAM, what would you type?

The command erase startup-config deletes the configuration stored in NVRAM. See chapter 4

What does the command routerA(config)# line cons 0 allow you to perform next?

The command line console o places you at a prompt where you can then set your console user-mode password. Chapter 4

Which of the following commands will allow you to set your Telnet password on a Cisco router?

The command line vty 0 4 places tiy ub a orinot that will allow you to set or change your Telnet pasword. See Chapter 4

What does the passive command provide to dynamic routing protocols?

The passive command, short for passive-interface, stops regular updates from being sent out and interface. However, the interface can still receive updates. See Chapter 6

What is the main reason the OSI model was created?

The primary reason the OSI model was created was so that different networks could interoperate. See Chapter 1

What command will display the line, protocol, DLCI, and LMI information of a interface?

The show interface command shows the line, protocol. DLCI, and LMI information of an interface.

Which command is used to determine if an IP access list is enabled on a particular interface?

The show ip interface command will show you if any outbound or inbound interfaces have an access list set. See Chapter 10

In a network with dozens of switches, how many root bridges would you have?

You should have only one root bridge per network. Chapter 8