Block 6 1A Flashcards
What are the four internetworking challenges?
Connectivity
Reliable service
Network management
Flexibility
A _______________ is a connection of INDIVIDUAL NETWORKS, connected by intermediate by intermediate devices that function as a single large network.
Internetwork
What are the two common devices used to address and overcome some of the internetworking challenges?
Routers and switches
In network segmentation… routers and switches are used to segment a network into separate _____________ and separate ___________________.
Collision domains
Broadcast domains
What is 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 and data stream?
Collision domain
Ethernet (802.3) utilities a process called __________ to prevent more than one device accessing the network cable at any one time and reduce the number of collisions.
CSMA/CD
A _______________ is a PORTION of the network, limited by its router connection to a specific group of host computers in a common LAN segment.
Broadcast domain
Comm between devices on the broadcast domain are via
Data link layer address (MAC)
All host in the broadcast domain share a common limited or local broadcast scheme of
255.255.255.255
All host in the broadcast domain also share a common logical network layer scheme( directed broadcast) also called a ___________.
Subnet
Actual communication across an internetwork is made possible by using _____________.
Communication protocols
What is the worlds most popular open-system (nonproprietary) protocol suite because they can be used to communicate across any set of interconnect networks and are equally well suited for LAN and WAN comm?
Internet protocols (also called the TCP/IP protocol suite)
Address schemes vary depending on the ___________ and the ____________.
Protocol family, OSI Layer
How many physical network connections do host have?
One (thus have only one data-link address)
What is an internetworking device that typically has multiple physical network connections?
Router (this having multiple data-link addresses.)
___________ addresses usually exist within hierarchical address space and are called virtual or logical address.
Network address
The relationship between a network address and a device is ____________
Logical and unfixed
What 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
Which encapsulates data to be sent over the network ?
Routed
What protocols build routing tables?
Routing protocols
Where do routed protocols occur?
Upper 5 layers of the OSI model
It’s two primary responsibilities are providing Connectionless, best effort delivery of packets through an internetwork based on Logical address and providing fragmentation and reassembly of packets to support data links with different MTU sizes.
Internet protocol (IP)
Packets at the receiving computer after crossing a network are identified as belonging to the same group by _____________.
Common identifier number
What protocol is designed for address resolution which is the process of mapping IP network addresses to to MAC addresses?
Address resolution protocol (ARP)
Protocols that enables network devices to learn MAC and network later address of other network devices.
Also functions as keep alives to ensure a connected router is functional.
Hello protocols
A network layer internet management protocol that provides message packets to report errors and other information regarding packet processing back to the source.
ICMP
This can used to test IP through the network. It sends an ICMP echo request to a destination IP address. If the destination machine receives the request it responds with an ICMP echo reply.
Ping
What are routing protocols responsible for?
Path determination(layer 3) and packet switching (layer 2)
____________ calls for routed to be calculated automatically at regular intervals by software in routing tables.
Dynamic routing
An IP routing table, which consist of destination address/next hop pairs, is used to enable _______________.
Dynamic routing
Do routers monitor whether packets get to their final destination?
No
Does IP provide for error reporting back to the source when routing anomalies occur?
No
Internet routing devices have traditionally been called ____________. Within the routing world this refers to routers that perform routing protocol functions between machines.
Gateway
A collection of networks under a common administration that share a common routing strategy.
Autonomous system (AS)
___________ routers are used for information exchange within autonomous systems.
Uses RIP,IGRP,OSPF,EIGRP
Interior gateway
____________ routers are used to move information between autonomous systems.
Uses BGP
Exterior gateway
The act of moving information across a packet switching internetwork from a source to a destination?
Routing
What are used to connect one LAN segment to another LAN segment within a routing domain and to connect an administrative area to other remote areas?
Routers
What are the 3 methods of path determination?
Routing metrics
Routing algorithms
Routing tables
A mathematical formula used to calculate the cost in network resources associated with a specific pathway to a destination network.
Initialize and maintain routing tables.
Routing algorithms
A standard unit of measurement such as path lengths that is used by routing algorithms to determine the optimal path to a destination.
Routing metrics
Electronic tables or databases containing updated information about available networks
Routing tables
What are the two ways routers communicate?
Broadcast and multicast
A message that generally consists of sending a whole routing table to all directly connected neighbor routers
Broadcast
A message sent between routers throughout a network to inform other routers of the STATE of the senders LINKS
Multicast
As the packet moves through the internetwork it’s later 2 (mAc) address are __________ but is layer 3(network ) address ____________.
Changed
Remains constant
Reasons for packet destruction
- Version # in packet header is wrong
- Time to live counter expires
- bit error or checksum (CRC) is wrong
- DOD security bits are set And Pc is unauthorized
- If packet must be fragmented In order and “allow fragmentation flag” has not been set.
What are the 3 external router components
Console port
Auxiliary port
Network interfaces
This router component allows you to configure the router remotely using a modem. Must be configured.
Configured through the console port or any network interfaces.
Auxiliary port
This router component allows you to configure the router locally by providing direct access to the router using a computer running terminal emulation software.
Does not have to be configured.
Console port
This router component is located on the motherboard or on separate interface modules.
Network interfaces
What are the four internal components and what are they used for?
1.ROM- diagnostics and boot up stored
2.FLASH- manufactures memory that holds the IOS.
3.NVRAM-store the startup-configuration file
4. RAM-working memory for the router
Contains configuration file, a copy of iOS, routing tables and any associated data.
Sends packets to a destination using the same or single path.
Single- Path algorithms
In this algorithm system all routers are peers of all others.
Must use the same subnet mask since it’s not included in the routing table
Flat algorithms
Called classless and supports VLSM.. Must include subnet mask….
Primary advantage is that it mimics the structure of most organizations and supports their system.
Hierarchical algorithms
Only used within a routing domain.
Used to exchange info within an autonomous system or routing domain
Intra-domain
Use with exterior gateway protocol.
Exchanges information within an between autonomous.
Inter-domain algorithms
Defined by the system administrator only as the only path to the destination.
Static routes
Defined by the system admin as the path to take when no route to the destination is known. Gateway of last resort.
Static route
A network layer protocol that exchanges information packets with other Internetwork routers in order to build and maintain a routing table.
Learned paths from other routers
Dynamic learned routers
The most common routing metric
Path length
Refers to dependability of each network link
Reliability
Refers to the length of time required to move a packet from source to destination through the Internetwork
Delay
Available traffic capacity of a link
Bandwidth
Refers to the degree to which a network resource, such as a router, is busy.
Load
Send packets to a destination using the same or Singlepath unless there is a topology change that affects the available route
Single-path algorithms
Supports multiple paths to the destination by load-balancing or load sharing
Mult-path algorithms
This routing structure is called “classless” routing and supports variable length subnet mask (VLSM)
Hierarchical
The primary advantage of hierarchal algorithm routing is that?
It mimics the structure of most organizations and therefore supports their traffic patterns well
Works within a routing domain…. Rip, IGRP, EIGRP , OSPF
Intra-domain algorithms
Used with exterior gateway protocol… BGP is an example
Inter-domain algorithms
Uses routing tables by using broadcast routing update messages when the network topology changes and at regular intervals.
Distance vector
These build a complete topological map of the entire area in memory which allows them to see the entire path to the destination network ensuring the path is valid and is the best available path
Link state algorithms
What are the three classes of routing protocols
Distance vector
Link state
Balanced hybrid
What are the two distance Victor protocols
RIP router information protocol
IGRP interior gateway routing protocol
This is considered a pure distance routing protocol it uses only one path length or hop count for its calculations to insert routes into routing tables.
Routing information
What is the max hop count for RIP
15
