Week 4: Intro to Routing Flashcards
What are Routed Protocols?
Protocols that can carry network layer information
What are Routing Protocols?
Protocols used by routers to make path determination choices & to share those choices with other routers
List some characteristics of Routed Protocols
Have packet headers that contain network layer addresses
Developed to support network consisting of multiple networks or subnetworks
List some characteristics of Routing Protocols
Performs dynamic route selection/decision
List some examples of Routed Protocols
IP, IPX, AppleTalk
List some Examples of Routing Protocols
RIP, OSPF, BGP
Define the term Routing
Routing refers to taking a packet from one device & sending it through the network to another device on a different network.
What are the minimum factors a router must know to route packets?
Destination address Neighbor routers Possible routes Best route How to maintain & verify routing information
What are the only concerns of a router?
Possible destination networks and the best path to each network. They don’t care about hosts
What are the fundamental functions of a router?
Best Path Selections and forwarding packets to destination
What are the two types of Dynamic routing?
Interior Gateway Protocol (IGP) and Exterior Gateway Protocol (EGP)
What are the 2 types of IGP’s?
Distance Vector Protocols (DVPs)
Link State Protocols (LSPs)
Name the three DVP Protocols
Routing Information Protocol (RIPv1/2)
Interior Gateway Routing Protocol (IGRP)
Enhanced Interior Gateway Routing Protocol (EIGRP)
Name the two LSP Protocols
Open Shortest Path First (OSPF)
Intermediate System-to-Intermediate System (IS-IS)
What is the difference between Static & Dynamic Routing
In static routing, next hop routes are manually configured in the routers. In dynamic routing, routers share information to learn the route to a certain destination
What Protocols are used in Dynamic Routing?
Routing Information Protocol (RIP)
Open Shortest Path First (OSPF)
Enhanced Interior Gateway Routing Protocol (EIGRP)
Border Gateway Protocol (BGP)
What is the basic procedure that all Routing Protocol Algorithms follow?
- Send & receive updates
- Calculate best path; install routes
- Detect & react to topology changes
List the criteria used to compare routing protocols
Time to Convergence
Scalability
Resource Usage
Implementation & Maintenance
List the two key concepts for Routing
Metric and Convergence
What is a Metric?
A value used to define the suitability of a particular route. Used by routers to determine which routes are better than others
What is Convergence?
A state where all routers on the internetwork share a common view of the internetwork routes
List the types of routing metrics used by routing protocols
Hop Count Bandwidth Delay Load Reliability Cost
What is an Autonomous System?
A system that uses IGPs as routing protocols; A group of routers under the control of a single administration
Where are IGP’s used?
Inside of an Autonomous System (AS)
Where are EGP’s used?
Between multiple Autonomous Systems (AS)
What is a Stub Network?
Networks with one route to the internet
What is a Stub Router?
Routers with only one route out
Usually the last in a chain of routers
What are the three Routing Principles?
- Every router makes its decision alone, based on the information it has in its own routing table
- The fact that one router has certain information in its routing table does not mean that other routers have the same information
- Routing information about a path from one network to another does not provide routing information about the reverse, or return path
What is a Default Static Route?
A route that will match all packets
What is Route Summarization?
The process of combining a number of static routes into a single static route
What is the benefit of summarizing a route?
Reduces the size of the routing table
What are the steps in configuring a summary route?
- Delete the current static route
- Configure the summary static route
- Verify the new static route
What is the Cisco IOS command to configure Static Routes?
ip route {network-address} {subnet-mask} {interface}
Can existing static routes set via ip route be modified?
No, the old static route must be deleted
What is the Cisco IOS command to delete a Static Route?
no ip route {network-address} {subnet-mask} {interface}
How is a Default Static Route configured via Cisco IOS commands?
Similar to configuring a static route, except that the Destination IP and Subnet Mask are all 0’s
e.g. ip route 0.0.0.0 0.0.0.0 {interface}
