1A Flashcards
Name the four internetworking challenges.
Connectivity, Reliable Service, Management, and Flexibility
A collection of individual networks, connected by intermediate networking devices that function as a single large network.
Internetwork
The challenge is to support communication between disparate technologies.
Connectivity
Individual users and entire organizations depend on consistent, reliable access to network resources.
Reliable Service
Networks must be managed to provide centralized support and trouble shooting capabilities for the internetwork.
Network Management
The final concern is necessary for network expansion or contraction along with new applications and services.
Flexibility
What are two primary devices used to address and overcome networking challenges?
Routers and Switches
A group of devices connected to the same physical media so that when two devices try to access the media at the same time, the two signals will collide with each other and destroy the data stream.
Collision Domain
IEEE developed what process to prevent more than one device from accessing the network cable at any one time and reduce the number of collisions.
CSMA/CD
A defined portion of the network, limited by its router connection to a specific group of host computers in a common LAN segment.
Broadcast Domain
Used to subdivide a network into individual broadcast domains.
Routers
A formal set of rules and conventions
Protocol
The internet protocols consist of a suite of communication protocols, of which the two best known are?
Transmission Control Protocol (TCP) and the Internet Protocol (IP)
Physical host generally only have __________ connection, and have only ____________ address
One Physical Network Connection
One Data-Link
Network addresses usually exist within a hierarchical address space and are sometimes called
Virtual or logical addresses
Routers and other internetworking devices require one network layer address per physical network connection for?
Each network layer protocol supported
_______ Build routing tables
Routing Protocols
Are protocols within a protocol suite that are responsible for providing the logical addressing that routers use to determine where to send the data packet on its way to the destination network.
Routed Protocols
A network layer protocol that contains addressing information and some control information that enables packets to be routed.
Internet Protocol (IP)
The primary routed network layer protocol in the Internet protocol suite
IP
The two main responsibilities of IP are?
Providing connection less, best effort delivery of packets through an internetwork based on logically assigned addresses; and providing fragmentation and reassembly of packets to support data links with different maximum-transmission unit MTU sizes
Packets will sometimes have to be broken down so that they do not exceed the maximum message size of the network
Maximum Transmission Unit (MTU)
The _____ _____ flag is set in the last fragment and all other fragments have the flag set to ____ _____ _____
Last Fragment
More packets follow
Another protocol that works between the data-link and network layers is called?
Address Resolution Protocol (ARP)
The process of mapping IP network addresses to Media Access Control addresses.
Address Resolution Protocol
Another protocol that enables network devices to learn the MAC and network layer addresses of other network devices.
Hello Protocol
Are sent at specific intervals to act as keep-alives to ensure a connected router is still functional.
Hello Protocols
A network layer Internet management protocol that provides message packets to report errors and other information regarding IP packet processing back to the source
Internet Control Message Protocol (ICMP)
ICMP generates several kinds of useful messages, including Destination Unreachable, time exceeded, router advertisement, router solicitation, Echo Request and Echo Reply
PING
Are network-layer protocols that are responsible for path determination and packet switching.
Routing Protocols
Implement routing algorithms to build and maintain routing tables.
Routing Protocols
Examples of Routing Protocols
RIP, IGRP, OSPF, EGIRP, and BGP
True or False
Routers do not monitor whether the packets get to their final destination.
False
This is the responsibility of ICMP
Refers specifically to a device that performs application-layer protocol translation between devices.
Gateways
Defined as a collection of networks under a common administration that share a common routing strategy.
Autonomous Systems (AS)
Are used for information exchange without autonomous systems and use a variety of Interior Gateway Protocols to accomplish this purpose.
Interior Gateway
Routers move information between autonomous systems, a border gateway is an example of this.
Exterior Gateway
Defined as an IP address on a layer 3 network device that serves as an access point to for form a network.
Default Gateway
The act of moving information across a packet switching internetwork for a source destination and involves two basic activities: determining optimal routing paths and transporting data packets.
Routing
Two main functions of a router are?
Path Determination and Packet Switching
For a router to perform its two major functions it must have what?
- A destination address from the layer 3 packet header
- Routing sources it can learn from (neighbors)
- A list of all possible routes to destination networks
- The ability to calculate and select the best routes using various metrics and algorithms
- Process to build, maintain, and verify its routing information through router communication messages.
Using information to determine the best, most efficient paths from available paths to known destination network.
Path Determination
The router uses the Routing Table to best decide how and where to forward packets across the internetwork.
Path Determination
Are a standard of measurement, such as path length, that is used by routing algorithms to determine the optimal path to the destination.
Routing Metrics
Initialize and maintain routing tables.
Routing Algorithms
Are electronic tables or databases containing updated information about available networks.
Routing Tables
Routers communicate with one another as part of?
Path Determination
Sending a whole table to all directly connected neighbor routers.
Broadcast (routing update message)
A message sent between routers throughout the network to inform other routers of the State of the Senders Link?
Multicast (Link state Advertisement)
A host determines that it must send a packet to another host, the hosts sends a packet addressed specifically to a routers physical MAC address in the layer two header
Packet Switching
Routers have the ability to discard packets which fall under?
Destruction of packets
Name the external components of a Router
Console Port, Auxiliary Port, and Network Interfaces
This port allows you to configure the router locally by providing direct access to the router using a computer running terminal emulation software.
Console Port
Allows you to configure the router remotely using a modem. This port must be configured before you can use it.
Auxiliary Port
A router can be configured over any of its?
Network Interfaces
This is where the diagnostic and boot up routines are stored
ROM
Manufacture memory thats holds the internetwork operating systems (IOS)
Flash
Used to store the startup-configuration file
NVRAM
Is the working memory for the router
RAM
