Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
21 Cards in this Set
- Front
- Back
|
What are three reasons for updating a routing table? |
1) Info on a shorter path to a destination has come in. 2) A path has come in for a new network. 3) An existing path has become longer or unavailable. |
|
|
What is the greatest weakness of routing protocols that use the distance-vector algorithm? |
Slow convergence. |
|
|
1) Info on a shorter path to a destination has come in. 2) A path has come in for a new network. 3) An existing path has become longer or unavailable.
These events signal? |
Reasons for updating a routing table. |
|
|
What system has its greatest weakness as slow convergence? |
Routing protocols that use the distance-vector algorithm. |
|
|
What's the difference between link-state and distance-vector routing? |
Distance vector tells its neighbors about the world, link state tells the world about its neighbors. |
|
|
What companion to IP protocol sends error messages? |
I C M P (Internet Control Messaging Protocol) |
|
|
What does ICMP do? |
It defines a collection of error messages that are sent back to the source host whenever a router or host is unable to process an IP datagram successfully. |
|
|
What are examples of ICMP messages? |
Link failure Unreachable host Failed reassembly process TTL has run out Checksum failed
|
|
|
An IP message fails to get to its destination, what happens now? |
The companion protocol ICMP (Internet Control Message Protocol) sends error messages back to the source. IP dumps the message.
|
|
|
What does IP protocol do when a message is undeliverable? |
It drops the message and leaves the companion protocol ICMP( Internet Control Message Protocol) to send back error messages. |
|
|
In addition to error messaging, what other message can be sent by ICMP (Internet Control Message Protocol)? |
A redirect message can be sent if the router knows a better way. The message is sent to the source who will update their table to include the shorter route. |
|
|
What is a redirect message? |
A message sent if the router knows a better way. The message is sent to the source who will update their table to include the shorter route. |
|
|
What protocol sends out a message to the source if the router has found a better path? |
ICMP Internet Control Message Protocol. |
|
|
What does ping do? |
Uses ICMP echo messages to determine if a node is reachable and alive. |
|
|
What does traceroute do? |
Determines the set of routers along the path to a destination. |
|
|
ICMP has 2 debugging tools. What are they? |
Ping Traceroute |
|
|
To what protocol do ping and traceroute belong? |
ICMP (Internet Control Message Protocol) |
|
|
What uses ICMP echo messages to determine if a node is reachable and alive? |
ping |
|
|
What debugging tool determines the set of routers along the path to a destination? |
traceroute |
|
|
What does VPN stand for? |
Virtual Private Network |
|
|
What does VPN do? |
It provides a virtual network accessible to a defined set of users, such as members of a particular company. |
