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316 Cards in this Set
- Front
- Back
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What 3 things are loaded when the router is initialized?
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1. Bootstrap
2. The Operating System 3. Configuration File |
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What does a router do if it cannot find a configuration file?
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Enters setup mode
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Where is the backup copy of the new configuration from setup mode stored?
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NVRAM
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What is the test called that the router performs when it powers up?
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POST
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After verifying Hardware functions what does the router do next?
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Software initialization
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Where is the bootstrap program loaded
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Rom
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What is the definition of Bootstrap
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A bootstrap is a simple preset operation to load instructions that in turn cause other instructions to be loaded into memory, or cause entry into other configuration modes
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Where are three places where the Cisco IOS can be found?
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1. Flash
2. TFTP Server 3. ROM |
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Where is the configuration file saved?
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NVRAM
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What 3 things does the POST Diagnostics from ROM verify.
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1. Basic CPU operation
2. Memory 3. Network Interface ports |
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How are configuration files loaded into main memory?
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one line at a time
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what do configuration commands do?
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1. Start routing
2. Supply addresses for interfaces 3. set media charachteristics and so on |
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If no valid configuration file exists in NVRAM, the OS executes a question driven configuration routine. What is this called
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System configuration Dialog or setup Dialog
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What command shows the backup config files
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Show startup-config
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What command shows the active config files
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Show running-config
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What command deletes the backup configuration file in NVRAM
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Erase startup-config
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What is the reboot command
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reload
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What is the command used to enter setup mode from the privledged exec prompt
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setup
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What is the purpose of setup mode?
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to bring up, quickly, a minimal configuration for any router that cannot find its configuration from some other source
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How do default answers appear in setup mode
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in brackets []
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what command can be pressed at any time to terminate the process and start over
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Control + C
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If you want to use the new configuration and you enter yes where will it be saved
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NVRAM
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What should you do if the MORE promp appears
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press space bar to continue
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What is the first global parameter you should enter?
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Host name
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What password is encrypted by Cisco proprietary software?
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Enable Secret
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How does the enable secret password appear on the config file?
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meaningless string of charachters
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If you answer yes to the setup configuration what will happen to the configuration file?
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it will be executed and saved to NVRAM
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if you want to change the setup configuration after you save it what must be done.
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You must configure it manually
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The script file generated by setup is additive. What does this mean?
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You can turn features on with setup but you can not turn them off.
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What 3 places can you load configuration files from?
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1. Console
2. NVRAM 3. TFTP server |
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What five pieces of information does the router use from the configuration files when it starts up?
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1. Cisco IOS Software version
2. Router Identification 3. Boot File Locations 4. Protocol Information 5. Interface Configuration |
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If there is no configuration file in the router, what mode do you enter to configure one?
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Setup
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What command will allow you to configure from a virtual terminal, a modem, or a console terminal?
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privledged EXEC configure
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What command configures manually from the console terminal.
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configure terminal
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What command displays the current configuration in RAM?
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Show running-config
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What command displays the saved configuration, which is the contents of NVRAM?
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show startup-config
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What command erases the contents of NVRAM?
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erase startup-config
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What does the command copy running-config tftp allow you to do?
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store a current copy of the configuration on a TFTP server.
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In copying a running-config to a host do you need to key the IP address of the host?
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Yes
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Do you need to name a config file copied to a TFTP server?
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Yes
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What mode do you need to be in, in order to manage the contents of NVRAM
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enable
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What command erases the contents of NVRAM
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erase startup-config
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Where is the runnning config stored?
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RAM
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Where is the startup or backup configuration file stored?
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NVRAM
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What command stores the current configuration into NVRAM?
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copy running-config startup-config
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What command displays the saved configuration?
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show startup-config
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If the screen prompt shows
Router(config-if)# what are you configuring? |
the interface
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If the screen prompt shows Router(config-subif)# what are you configuring?
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the subinterface
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What mode are you in when you apply commands that affect the system as a whole?
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Global configuration
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What do you type to enter global configuration mode from the terminal
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Configure Terminal or
Config T |
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What command do you key to configure a routing protocol?
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Router "protocol" for example to configure RIP you type
Router RIP |
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What mode are all router interfaces automatically in?
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administratively down mode
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What is the clocking signal on a serial link?
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DCE
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What tyoe of devices are, by default, cisco routers?
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DTE
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what command sets the clockrate?
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clockrate
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What command establishes a password on the console terminal?
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line console 0
or line con 0 |
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What command establishes password protection on incoming telnet sessions?
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line vty 0 4
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What command uses Cisco proprietary encryption process to alter the password character string?
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enable secret password
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If you do not configure a router name, what is the default name?
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router
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What mode must you be in to change the routers name?
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Global Config
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What does the command banner motd allow you to do?
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Configure a message-of-the-day banner to be displayed on all connected terminals at login
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What delivery method does IP use?
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Best Effort
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What are three reasons data may fail to reach its destination?
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1. Hardware Failure
2. Improper configuration 3. Incorrect routing info |
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What does IP use to notify the sender that the message couldnt be delivered?
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ICMP
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What type of message provides information or configuration parameters to hosts?
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Control messages
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What component of TCP/IP notifies the sender that a data transmission has failed?
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ICMP
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What is the acronym for Internet Control Message Protocol?
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ICMP
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Does a router know the exact path a datagram took to get to the router?
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No
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What is the ONLY information a router has about a datagram?
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Only the source and destination IP address of the datagram
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Does ICMP correct network problems?
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No
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Does ICMP notify the intended receiver that there was a problem delivering the packet?
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No
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Why dont error created by ICMP messages generate their own ICMP message?
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error reports could generate more error reports, causing increased congestion on an already ailing network
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What 3 addresses are needed in TCP/IP configuration if datagrams are to travel outside the local network
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1. IP Address
2. Subnet mask 3. Default gateway |
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What two things must a router have in order to send datagrams?
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1. TCP/IP properly configured on it's interfaces
2. An appropriate routing protocol |
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What is the term that is used when a destination network is not accessable?
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Unreachable network
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What happens if the destination device recieves the ICMP echo request?
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It formulates an echo reply message to send back to the source of the echo request
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What command initiates an echo request?
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ping
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If an echo request is succesful between the source and destination what does that mean.
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This confirms ip connectivity betweeen the two devices
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What would be created if two routers continually route a datagram back and forth?
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Loop - travels in circles
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What is the maximum hop count for RIP?
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15
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What does TTL stand for?
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Time to Live
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What 3 fields are common to all ICMP messages?
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1. Type
2. Code 3. Checksum |
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What are four reasons datagrams might not make it to their destination?
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1. Hardware failures
2. Improper protocol configuration 3. down interfaces 4. Incorrect routing information |
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If a "3" appears in the type field what does that mean?
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Destination Unreachable
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What does the "code value" indicate?
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The reason a packet could not be delivered
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What is usually needed to forward a datagram from a token-ring to an ethernet network?
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Packet fragmentation
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If a datagram header has an error what will a device like a router do?
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It sends an ICMP type 12 parameter problem message to the source
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When the code value of teh problem message reaches 0, what will the pointer field indicate?
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the octet of the datagram that produced the error
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Why is a control message sent?
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To inform hosts of conditions such as network congestion or a better gateway.
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How are ICMP control messages sent?
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Inside IP datagrams
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What is another term for "gateway"
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router
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What is the only device that can initiate a Redirect/Change request message?
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router
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How is a redirect/change configured on a Cisco router?
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It's the default
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What allows a host to ask for the current time according to the remote host?
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The ICMP timestamp message request
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What are the 2 type fields on an ICMP time stamp message?
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13 (Timestamp request) or
14 (Timestamp reply) The code field value is always set to 0, because there are no additional parameters available. |
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What 3 things are contained in the ICMP timestamp reply message
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1. the originate timestamp
2. the receive timestamp 3. transmit timestamp |
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What 2 things affect true transit time?
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1. Traffic
2. Congestion on the network |
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What 2 protocls are now used to allow a host to find its network number?
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1. BOOTP
2. DHCP |
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What type of message is sent out when a host doesnt know the network address?
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Address mask request
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What is the mulicast address for router discovery?
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224.0.0.2
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What happens if a router receives a multicast request but isnt configured for multicasting?
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It doesnt answer the request
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If the default gateway is missing, what message is genereated by the host?
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router solicitation
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What happens when there is too much congestion on a network?
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Packets are dropped
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Why dont Cisco routers send source quench messages(by default)?
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because the source-quench message may itself add to the network congestion
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What type of offices might use source quench messages
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SOHO
small office home office |
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What is the standard for internetwork communications?
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TCP/IP
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What is the transport protocol for the internet?
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TCP/IP
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What is the function of the TCP/IP protocol suite?
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Responsible for the reliable transport and regulation of data flow from source to destination
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Prior to data transmission, the 2 communicating hosts go through a synchronization process to establish a virtual connection for each session between hosts. This process is called what?
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Three way hand shake
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Describe the process of a three way hand shake?
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1. The source host sends the destination host a request for communication. This is done by sending a sequence number
2. The destination host sends back and Acknowledgement of the sequence number and then adds a 1 to it and sends it back. 3. The source host acknowledges the sequences number+1 that the destination host sent and begins transmitting |
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DoS stands for?
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Denial of Service attack
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Describe SYN flooding?
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SYN flooding exploits the normal three way handshake and causes targeted devices to acknowledge to source addresses that will not complete the handshake
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Describe DoS attack?
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the hacker initiates a SYN but spoofs the source IP address. Spoofing is a term used when the receiving device replies to a non-existant, unreachable ip address and then is placed in a wait state until it recieves the final acknowledgement from the initiator
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What are some defense mesures for SYN flooding and DoS attacks?
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system administrators may decrease the connection timeout period and increase the connection queue size. Software also exists that can detect these type of attacks and initiate defensive measures
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Describe how windows provides flow control?
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data must be broken into smaller pieces to allow for proper data transmission
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What is the purpose of TCP applying sequence numbers to segments?
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so that the recieving node can reassemble bytes in the correct order
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What does TCP do if a sequence number is missing in a series?
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That segment is retransmitted
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TCP uses positive acknowledgement and retransmission (PAR) for what?
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to control data flow and confirm data delivery
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Name the field responsible for trancking of transmitted and received bytes?
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the Acknowledgment Number field
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What two protocols does the Transport layer provide?
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1. TCP
2. UDP |
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What layer 3 protocol is connectionless?
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IP
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Which protocol is a connection oriented reliable protocol?
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TCP
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What protocol is connectionless and unreliable?
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UDP
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What advantage does UDP provide over TCP?
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Speed
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TCP provides services for what applications?
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1. FTP
2. HTTP 3. SMTP 4. DNS |
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UDP is the transport layer protocol used by what applications?
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1. DNS
2. TFTP 3. SNMP 4. DHCP |
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UDP is unreliable - so what layer provides error detection?
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UDP does not use windowing or ACK's so APPLICATION LAYER protocols must provide error detection
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What are port numbers used to keep track of?
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the different conversations that cross the network at the same time
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Both TCP and UDP use _________ to pass information to upper layers?
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port or socket numbers
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What port is used for FTP application?
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21
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What port numbers are used for public applications?
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Below 255
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What is port number 53 used for?
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DNS
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What is the port used for telnet?
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23
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The IP address gets the packet to the _______?
The TCP or UDP port number guarantees that the packet is passed to the correct ___________? |
correct server
application |
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Port numbers in the range of 0 - 1023 used to select proper applications are considered public port numbers and are controlled by ___________?
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Internet Assigned Numbers Authority (IANA)
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IP addresses gets the packet to the correct server but ___________ GUARANTEES the packet is passed to the correct application?
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TCP or UDP
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Be able to determine the difference between TCP segments and UDP segments What information do UDP segments not contain?
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No sequence numbers or Acknowledgement fields
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List the 3 categories of port numbers.
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1. Well known ports
2. Registered ports 3. dynamic or private ports |
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_______________ are located at he transport layer and are serviced by the network layer?
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Port numbers
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The Network layer assigns the logical address or ____________, and is then serviced by the Data Link layer, which assigns the physical address or the ______________.
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IP address
MAC Address |
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What is a sequential list of permit or deny statements that apply to addresses or upper layer protocols?
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An ACL
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What are two things a router can do with a packet?
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Accept or Deny
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How are ACL's defined?
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On a per-protocol, per direction (in or out), or per port basis
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What happens to packets if an ACL is not configured on a router?
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all packets passing through the router will be allowed on all parts of the network.
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Where are packets either accepted or rejected due to an ACL?
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at the interface
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How does a router read an ACL?
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From top to bottom
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What happens to the ACL statements once a match is found in the list?
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the accept or reject action is performed and no other ACL statements are checked
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What happens if additional condition statements are needed in an access list.
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The entire ACL must be deleted and recreated with new condition statements.
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What is placed at the end of EVERY ACL?
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Implicit Deny Any statement
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What mode must you be in to create an ACL?
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Global Config
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What are the 2 steps in creating an ACL
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1. Create the ACL
2. Apply it to an Interface |
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What are 2 directions ACL's can be placed?
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In
Out |
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Where should a standard ACL be placed?
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Closest to the destination
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Where should an extended ACL be placed
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Closest to the source
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What happens if no match is found on an ACL list?
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The packet is denied
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What does a 1 mean in wildcard masking?
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Ignore
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What does a 0 mean in wildcard masking?
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Check
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What IP Address and subnet mask will the word any substitute for?
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0.0.0.0 255.255.255.255
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What command shows ALL the ACLs on a router
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show access-lists
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What do standard ACL's check?
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Source IP address
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What is the default wildcard mask?
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0.0.0.0
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What 4 things can an Extended ACL check?
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1. Source Address
2. Destination Packet Address 3. protocol 4. Port number |
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What type of echo packet is sent to the sender if the packet is discarded?
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destination was unreachable
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Can you use the wildcard host or any keywords in the command?
|
Yes
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What does the ip access-group command link?
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an existing extended ACL to an interface
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What version of CISCO IOS allowed for named ACL's?
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11.2
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What mode must you be in to configure a named ACL?
|
Global Config
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Where do you place Extended ACLs?
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As close to the source as possible
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Where do you place standard ACLs?
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As close to the destination as possible
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Who does a firewall try to keep out the intranet?
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intruders that come from the global internet
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Where are most firewalls placed?
|
between the internal network and an external network, such as the internet
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What are routers that are situated on the boundries of a network?
|
Border routers
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What 2 types of ACLs are used on packets traveling through a router?
|
Standard
Extended |
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What are the numbers of the virtual ports on a router
|
0, 1, 2, 3, 4
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Why should identical restrictions be placed on all vty lines?
|
Its impossible to control which line a user will connect on
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What does a router do when it determines that a route is the best path to a destination?
|
It adds that route to its routing table.
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What are the 2 most time consuming jobs of a network administrator?
|
Network testing and troubleshooting
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What type of equipment causes the most difficult network problems?
|
Routers
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What is the function of a router?
|
To determine the best path from a source to a destination
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What do routers read to make packet forwarding decisions?
|
Contents of their IP routing table
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What does the command show ip route display?
|
The contents of their IP routing table
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What is a manually configured route called?
|
Static Route
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What is a route that can change automatically as neighboring routes update each other with new information?
|
Dynamic Route
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What is used when the router is unable to match a destination network with an entry in its routing table?
|
Default route
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What command establishes a default route in networks using dynamic routing protocols?
|
ip route 0.0.0.0 0.0.0.0
or ip default-network |
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What layer determines the best path for a packet?
|
Network Layer (Layer 3)
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What device determines the best path and forwards the packet from an incoming interface to an outgoing interface
|
router
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what address is used to get packets from source to destination?
|
Layer 3 Address
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What address never changes no matter how many hops a packet takes?
|
Source and Destination IP Address
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What address changes at each hop or router?
|
MAC Address
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What metric does rip v1 use?
|
Hop Count
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What metric is better higher or lower
|
Lower
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What layer should you start with when testing network problems?
|
Layer 1
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What is the most common problem on IP networks?
|
Errors in the addressing scheme
|
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What is the most important part of troubleshooting?
|
Documentation
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What layer would a transciever problem be at?
|
Layer 1
|
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What layer would an improperly configured serial interface be at?
|
Layer 2
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What layer would an incorrect IP address be?
|
Layer 3
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What command is used to test connectivity
|
Ping
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What is another name for the "indicator" light on a NIC card that indicates a valid connection
|
Link Light
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What should you do if the interface has indicator lights that do not show a valid connection?
|
Check for faulty or incorrect cabling
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What 3 things are displayed when a ping packet finds a specified system and returns?
|
Minimum, Maximum, and Average time it takes for a packet to find a specified system and return
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What will the command show ip protocol show?
|
Shows the current state of the active routing protocols
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What does IGRP use to balance the load on multiple links?
|
Variance
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What 3 things are displayed when a ping packet finds a specified system and returns?
|
Minimum, Maximum, and Average time it takes for a packet to find a specified system and return
|
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What does 5 exclamation points indicate when performing a ping?
!!!!! |
A successful connection
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What command would you use to perform more extensive ping tests?
|
Extended Ping
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Which ICMP message type notifies the source host that a receiving host or network is not available?
|
Destination Unreachable
|
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What layer does Telnet test
|
All Layers
|
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What line from show interfaces output would indicate a layer 2 problem?
|
The line that says
Interface UP Line protocol DOWN |
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What would an Increasing number of Carrier transitions counts on a serial link indicate?
|
Bad Link or defective CSU/DSU
|
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What are messages sent by one network device to inform another network device that the virtual circuit between the two is still active?
|
Keepalives
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Who does CDP allow you to discover information about?
|
Directly connected Cisco devices
|
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What command is used to discover routes that packets take when traveling to their destination?
|
traceroute
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What command shows the entries for all known networks and subnetworks, and how that information was learned
|
show ip route
|
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what commadn would identify a router that is delivering bad router information?
|
Show IP protocols
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What command would allow you to check a cable connection if you were in LA and a router was in New York?
|
Show controllers
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What command will turn off all diagnostic output?
|
no debug all
or undebug all |
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What command will show what is being examined by a debug command?
|
show debugging
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|
MAC Addresses are how many bits in Length?
|
24
|
|
|
Describe communicaton between 2 devices on a LAN
|
The source device encapsulates data in a frame with the MAC address of the destination device and then transmits it. Everyone on the LAN sees it but the devices with non matching addresses otherwise ignore the frame.
|
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|
What are some functions associated with Frames
|
1. Identifies which computers are communicating with one another
2. Signals when communication between individual computers begins and when it ends 3. Flags corrupted Frames |
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|
Media Access Control Refers to what?
|
Rules that determine which computer on a shared-medium is allowed to transmit the data
|
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|
How do you describe CSMA/CD networks?
|
One node's transmission traverses the entire network and is received and examined by every node.
|
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What are the important Data Link Layer (Layer 2) functions?
|
Logical Link Control
Addressing Media Access Control |
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What is true of a deterministic MAC protocol?
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It allows hosts to "take turns" sending data
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Fast Ethernet Supports up to what transfer rate?
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100 Mbps
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What are the 2 Gigabit over fiber cable specifications?
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1000Base-LX
1000Base-SX |
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What is the transmission medium for 1000BASE-SX?
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Short-wave laser over multimode fiber
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4D-PAM5 encoding method is used in which Gigabit ethernet?
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802.3ae
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What happens when 1000BASE-T sends and receives data in full-duplex mode on the same conductor?
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A permanent collision on the wire
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What is the maximum transmission distance supported by 10 Gigabit Ethernet?
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40 Kilometers
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What are 3 features of microsegmentation?
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1. It enables dedicated access
2. It supports multiple conversations at any given time 3. It increases the capacity for each workstation connected to the network |
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What do LAN switches use to make forwarding decisions?
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MAC Addresses
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What best describes one function of Layer 3, the network layer, in the OSI model?
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It determines the best path for traffic to take through the network.
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What function allows routers to evaluate available routes to a destination and to establish the preferred handling of a packet?
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Path Determination
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How does the network layer forward packets from the source to the destination?
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By using A routing table
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What 2 parts of a network layer address do routers use to forward traffic through a network?
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Network address and destination IP address
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What best describes a routed protocol?
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Its address provides enough information to allow a packet to be forwarded from host to host.
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What best describes a routING protocol?
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A protocol that accomplishes routing throgh the implementation of an algorithm
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Whats an advantage of distance vector algorithms?
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They are computationally simple
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What describes Link State algorithms
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It recreates the exact topology of the entire network
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Why do routing loops occur?
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Slow convergence occurs after a modification to the internetwork.
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Describe the concept describing EIGRP as a balanced hybrid routing protocol?
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Being that EIGRP is a distance vector routing protocol, it determines best paths, but topology changes trigger routing updates
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What is a network with only one path to a router called
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Stub network
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What best describes a default route?
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Route used when the destination network is not listed explicitly in the routing table
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What kind of entries does a router initally refer to?
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Entries about networks or subnets that are directly connected
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What are exterior routing protocols used for?
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To communicate between autonomous systems.
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If you suspect that one of the routers connected to your network is sending bad routing information what command would you use to check?
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router> show ip protocol
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Why would you display the routing table?
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To identify destination network addresses and next-hop pairs
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If you want to learn which routing protocl a router was configured with what command structure should you use?
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router> show ip protocol
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An administrative distance of 15 indicates what?
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The routing information source is relatively trustworthy
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If you wanted to see RIP routing updates as they are sent and received what command would you use?
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router# debug ip rip
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Most NICs have what type of lights that show whether there is a valid connection?
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Indicator
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What best describes TCP/IP?
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Its a suite of protocols that can be used to communicate across any set of interconnected networks.
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Why is sequence numbering in the TCP 3 way handshake open connections used?
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To ensure lost data can be recovered if problems occur later
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What is teh function of ARP?
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It is used to map an unknown IP address to a known MAC address?
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What best describes window size?
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The number of bytes that can be transmitted while awaiting an acknowledgement
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What does a TCP sliding window do?
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Its a method of flow control for network data transfers using the receiver's window size.
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What command displays contents of the IP routing table?
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Show IP route
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Why are default routes used?
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Defaults are used when the router is unable to match a destination network with a more specific routing table entry.
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What is a metric?
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The measurement used by a router to determine the best route.
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When a router receives an incoming packet, what does it do?
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It checks destination address and attempts to associate it with the next hop.
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What are the most common type of problems that occur on IP networks?
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Errors in the addressing scheme.
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What is the most important part of the troubleshooting process?
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Documentation
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What layer of OSI would these errors occur?
Broken Cables DTE Device Problems Transciever problems |
Layer 1
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What layer of OSI model would you find these errors?
Incorrect IP address Incorrect Subnet mask |
Layer 3
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What does TX and RX stand for.
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These are the link lights on a device.
TX = Transmitting Data RX = Receiving Data |
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What is ping used for?
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Ping is used to test network connectivity
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What does a succesful telnet indicate?
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That all layers of the OSI model are functioning properly.
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What is the single most important tool to discover Layer 1 and Layer 2 problems with the router?
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The show command
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What are 3 possible causes of an interface being up and the line protocol being down
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1. No Keepalives
2. No Clockrate 3. Mismatch Encapsulation |
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Should you use debug during peak network times?
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No
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What troubleshooting utility is used to discover the routes packets take when traveling to their destination?
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Traceroute
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What is the synchronization process called that TCP uses to prepare for data transmission?
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3 way handshake
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What does DoS stand for and what is it designed to do?
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DoS means Denial of Service attack.
Designed to bring down a server maliciously |
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What does window size determine?
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window size determines the amount of data that can be transmitted at one time before a destination responds with an ACK
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What are sequence numbers used for?
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To help recieving nodes reassemble data that was received in the right order.
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What provides error detection in UDP?
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Application Layer Protocols
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What are the 2 types of routes
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Static
Dynamic |
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When specifying a static route, the administrator has two options for indicating the gateway. What are they?
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1. Next hop address
2. Outbound Interface |
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What command is used to configure a static route
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ip route "address" "subnet mask" "next hop"
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What types of routes are used to route packets with destinations that do not match any of the other routes in a routing table?
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Default routes
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What is the command to setup a default route?
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IP route 0.0.0.0 0.0.0.0
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What command do you use to view the routing table?
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show IP route
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What is a routing protocol?
|
A routing protocol is used by routers to update routing tables.
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What is a routed protocol?
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A routed protocol is used by routers to direct traffic.
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What is an Autonomous system?
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An Autonomous system is a collection of networks under a common administration that share a routing strategy. These may be run by one or more operators.
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What is the goal of a routing protocol?
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The goal of a routing protocol is to build and maintain routing tables.
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List the 2 categories of routing protocols?
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Distance Vector
Link State |
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Using distance vector routing, where does a router get its routing table updates?
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From Adjacent routers
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What does the network command do when configuring routing protocols?
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Determines which interface sends and receives router table updates
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When using RIP what happens to a packet if the hop count is greater than 15?
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The packet is discarded
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What type of routing is Border Gateway Protocol (BGP)?
|
Exterior Routing Protocol
Used from ISP to ISP |
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What types of routing protocols have Fast convergence?
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Link State
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What types of routing protocols have Slow convergence?
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Distance Vector
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Distance Vector Algorithms call for each router to send __________________ to each of its adjacent neighbors?
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entire routing table
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What can occur if slow convergence occurs on the network as a result of changes to the network causing inconsistant routing entries?
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Routing Loops
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Describe Route Poisoning?
|
This is the notification given to a router that a route is down by giving it a number that represents an Infinate number of hops.
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When is a triggered update sent?
|
Every 30 seconds on RIP or whenever a routing table changes
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What are the 4 charachteristics of RIP?
|
1. Distance Vector Protocol
2. Metric is Hop Count 3. If Hop Count > 15 packet is discarded 4. updates sent every 30 seconds |
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|
what command enables RIP?
|
router rip
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What does configuring "ip classless" do on a router?
|
It allows router to ignore classful boundries of networks in its routing table and route to the default route.
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What does RIP use to reduce routing loops and count to infinity?
|
1. Split Horizon
2. Poison Reverse 3. Hold down Counters 4. Triggered updates |
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List 2 common ways to verify RIP is configured properly.
|
1. Show IP route
2. Show IP protocols |
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What does using the passive interface command prevent?
|
It prevents an interface from sending routing updates
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What is IGRP?
|
A distance vector routing protocol that was developed by Cisco.
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RIP Sends routing updates every 30 seconds. How often does IGRP send updates?
|
Every 90 Seconds
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What are the 4 Metrics used by IGRP?
|
Bandwidth
Delay Reliability Load |
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|
What command do you use to configure IGRP?
|
router igrp "Autonomous system number"
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|
Which routing protocol converges faster RIP or IGRP?
|
IGRP
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|
What is ICMP and what does it do?
|
ICMP - Internet Control Message Protocol
ICMP is used to notify sender that there was an error in a delivery address |
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|
How are ICMP messages delivered?
|
Encapsulated in datagrams and transferred just like other data.
|
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|
What does TTL stand for?
|
TTL = Time to live, which is the number of hops left before a packet is discarded
|
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When a destination is unreachable what does ICMP do?
|
It assigns a code as to why the destination is unreachable (field code)
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What are control messages used for?
|
Control messages are used for informing hosts of network congestion or existance of a better gateway to a remote network.
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