cisco 2 Flashcards

Transmission Control Protocol
Terms Definitions
Challenge Questions
7.  Compare and contrast the messages that application layer protocols such as DNS, HTTP, SMB, and SMTP/POP exchange between devices to enable data transfers to occur.
Packet Tracer
A drag-and-drop network simulator developed by Cisco to design, configure, and troubleshoot network equipment within a controlled, simulated program environment.
The process of obscuring information to make it unreadable without special knowledge, sometimes referred to as scrambling. The process takes the data to be encrypted and applies a mathematical formula to it along with a secret number (called an encryption key). The resulting value, which is called an encrypted packet, is sent through a network.
HTTPS can use authentication and encryption to secure data as it travels between the client and server.
Cisco, Ansi, Q.933a.
What does LMI do?
Open Systems Interconnection (OSI)
International standardization program created by ISO and ITU-T to develop standards for data networking that facilitate multivendor equipment interoperability.
The OSI model describes the entire communication process in detail, and the TCP/IP model describes the communication process in terms of the TCP/IP protocol suite and the way it functions.
Know the details of the OSI model to understand the entire network communication process
Know the TCP/IP model to understand how the process is implemented in current networks
The Open Systems Interconnections (OSI) model, known as the OSI model, provides an abstract description of the network communication process.
Internetwork Protocol
The most common internetwork protocol is Internet  Protocol (IP).  IP is responsible for taking the formatted segments from TCP, encapsulating them into packets, assigning the appropriate addresses, and selecting the best path to the destination host.
A request for information. Queries are answered with replies.
Computer operating systems also have a utility called nslookup that allows the user to manually query the name servers to resolve a given host name.
A notification sent from one network device to another to confirm that some event (for example, receipt of a message) has occurred.
Instant Messaging (IM)
Real-time communication between two or more people through text. The text is conveyed through computers connected over a network such as the Internet. Files can also be transferred through the IM program to share files. A good example of an IM program is Microsoft Messenger.
The process by which a device adds networking headers and trailers to data from an application for the eventual transmission of the data onto a transmission medium.
The process of adding control information as it passes through the layered model is called encapsulation.
Physical Address
A data link layer address, for example, a MAC address.
DNS Resolver
The client part of the DNS client-server mechanism. A DNS resolver creates queries sent across a network to a name server, interprets responses, and returns information to the requesting programs.
The DNS client, sometimes called the DNS resolver, supports name resolution for the other network applications and other services that need it.
Segmenting Data
The Transport layer breaks the data into smaller pieces, which are better suited for transmission.  These pieces are called segments.
This process includes the encapsulation required on each piece of data.  Each piece of application data requires headers to be added at the transport layer to indicate to which communication it is associated.
Which Layer 4 protocol is used for a Telnet connection between two Certkiller  routers?  
Answer:  D Explanation: 
 TCP is a reliable connection-oriented protocol. TCP uses acknowledgments, sequencing,and flow control to ensure reliability. Telnet uses TCP port 23.
IP (Internet Protocol)
Network layer protocol in the TCP/IP stack offering a connectionless internetwork service. IP provides features for addressing, type-of-service specification, fragmentation and reassembly, and security. Documented in RFC 791.
Internetwork devices
Connect one network to one or more other networks. Routers are the main example.
Server Message Block (SMB)
An application level network protocol mainly applied to shared access to files, printers, serial ports, and miscellaneous communications between nodes on a network.
Server Message Block (SM) is a client/server file-sharing protocol.  It is a request response protocol.  Unlike the file sharing supported by FTP, clients establish a long-term connection to servers.  After the connection is established, the user of the client can access the resources on the server as if the resource is local to the client host.
SMB file-sharing and print services have become the mainstay of Microsoft networking.
Transmission Control Protocol (TCP)
TCP is a connection-oriented protocol, described in RFC 793.  TCP incurs additional overhead to gain functions.  Additional functions specified by TCP are same-order delivery, reliable delivery, and flow control.  Each TCP segment has 20 bytes of overhead in the header encapsulating the application layer data, whereas each UDP segment has only 8 bytes of overhead.
Lowest IP address.
Whats the default query interval for IGMPv2?

DRAG DROPYou work as a network administrator at Certkiller .com.Your boss, Mrs. Certkiller, is interested in the OSI layers. Match the terms with the appropriate layer. Some options are not used.

Explanation:  The Transport layer segments and reassembles data into a data stream. Services locatedin the Transport layer segment and reassemble data from upper-layer applications and unite it into the same data stream. They provide end-to-end data transport services andcan establish a logical connection between the sending host and destination host on aninternetwork.TCP and UDP transport protocol lies on Transport Layer, which break down the datacoming from upper layer into segment.Windows are used to control the amount of outstanding, unacknowledgeddata segments that is also on Transport Layer.Network Layer:The Network layer (also called layer 3) manages device addressing, tracks the location ofdevices on the network, and determines the best way to move data, which means that theNetwork layer must transport traffic between devices that aren't locally attached. Routers(layer 3 devices) are specified at the Network layer and provide the routing serviceswithin an internetwork.Protocol Data Packets (PDU) on Network Layer is known as Packets. Routing andRouted protocols are lies on Network Layer.Routing Protocol: RIP, IGRP, EIGRP, OSPF, BGPRouted Protocol: IP, IPX    
Intermediary Devices
Role - management of data as it flows through the networkIntermediary devices connect the individual hosts to the network and can connect multiple individual networks to form an internetwork.use the destination host address with information about the network interconnections to determine the path messages should take
SMTP commands and repies
The SMTP protocol message format uses a rigid set of commands and replies.  These commands support the procedures sused in SMTP, such as session initiation, mail transaction, forwarding mail, verifying mailbox names, expanding mailing lists, and the opening and closing exchanges.  Some of the commands specified in the SMTP protocol are:
HELO: Identifies the SMTP client process to the SMTP server process
EHLO: Is a newer version of HELO, which includes services extensions
MAIL FROM: Identifies the sender
RCPT TO: Identifies the recipient
DATA: Identifies the body of the message
Identifying the Applications
To pass data streams to the proper applications, the transport layer must identify the target application.  To accomplish this, the transport layer assigns an identifier to an application, called a port number, which is unique to the application and host.
Full duplex.
What is the max-age timer used for in STP?
"shape fecn-adapt"
When a BECN is received, by how much is the rate slowed down?
Benefits of a Layered Model
Defines common terms that describe the network functions to those working in the industry and allows greater understanding and cooperation
Segments the process to allow technologies performing one function to evolve independently of technologies performing other functions
Fosters competition because products from different vendors can work together
Provides a common language to describe networking functions and capabilities
Assists in protocol design, because protocols that operate at a specific layer have defined information that they act upon and a defined interface to the layers above and below
Dynamic or Private Ports
TCP and UDP ports that range from 49152 to 65535 and are not used by any defined server applications.
How do you define a secondary vlan?
vlan <vlan> private-vlan <community>
Wide Area Network (WAN)
A network that is used to connect LANs that are located geographically far apart.Typically does not have users.
2.  The TCP/IP application layer consists roughly of which three OSI layers?
B.  The functionality of the TCP/IP application layer protocols fits roughly into the framework of the top three layers of the OSI model:  application, presentation, and session.
Everything is working between the frame-relay switch and the router.
What does the frame-relay status of deleted mean?
Sending and Receiving Process -> Email
1. An end user, using an em-mail application, creates data.  The application layer coeds the data as e-mail and sends the data to the transport layer
2.  The message is segmented, or broken into pieces, for transport.  The transport layer adds control information in a header so that it can be assigned to the correct process and all segments put into proper order at the destination.  The segment is sent down to the internetwork layer.
3.  The internetwork layer adds IP addressing information in an IP header.  The segment is now an addressed packet that can be handled by routers en route to the destination.  The internetwork layer send the packet down to the network access layer.
4.   The network access layer creates an Ethernet frame with local network physical address information in the header.  This enables the packet to get to the local router and out to the web.  The frame also contains a trailer with error-checking information.  After the frame is created, it is encoded into bits and sent onto the media to the destination.
5.  At the destination host, the process is reversed.  The frame is decapsulated to a packet, then to a segment, and then the transport layer puts all segments into the proper order.
6.  When all data has arrived and is ready, it is sent to the application layer, and then the original application dta goes to the receiver's e-mail application.  The message is successful.
Name the hello timers on EIGRP?
5 seconds on fast links.60 seconds on slow (<T1) links.
3.  HTTP is used to do which of the following?
C.  Hypertext Transfer Protocol (HTTP) is used to transfer files that make up the web pages fo the World Wide Web.  DNS is used to resolve Internet names to IP addresses, and Telnet is used to provide remote access to servers and networking devices.
Using advertise-maps in BGP. Can you use extended access-lists to match routes?
From testing, it appears you can use extended ACL's when matching on WHAT route to advertise, NOT the conditional route.
QUESTION 5: Cisco is the leader in the router market space. What basic functions do their routers perform in a network? (Choose two)
A. The microsegmentation of broadcast domains
B. Path selection
C. Packet switching
D. Bridging between LAN segments
Answer: B, C
Explanation: The primary functions of a router are: Packet Switching and Path Selection. It is the routers job to determine the best method for delivering the data, and switching that data as quickly as possible.
A syslog message is generated, but the port is NOT put into the err-disabled state.
The port will be put into an undetermined state.
 Acknowledgements, sequencing, and flow control are functions that are handled bywhich layer of the OSI model?  A. Layer 5
B. Layer 4
C. Layer 7
D. Layer 6
E. Layer 3
F. Layer 2
G. Layer 1
Answer: B
Challenge Questions
4.  compare and contrast client/server with peer-to-peer data transfer over networks.
Any combination of hardware device and/or software application designed to protect network devices from outside network users and or malicious applications and files.
Information systems that allow the creation of a document or documents that can be edited by more than one person in real time.
HTTP, one of the protocols in the TCP/IP suite, was originally developed to publish and retrieve HTML pages and is now used for distributed, collaborative information systems.
CDP is running between two Certkiller devices. What information is supplied by CDP?
(Select three)
A. Device Identifiers
B. Capabilities list
C. Platform
D. Route identifier
 E. Neighbor traffic data
Encoding messages refers to the way data is converted to patterns of electrical, light, or electromagnetic energy and carried on the medium.Encode - To change the energy levels transmitted over some networking medium to transmit bits over that medium.
Wireless Media
Connects local users through the airEncoding - Electromagnetic waves
A form of transmission where one device transmits to all devices within the network or on another network.
The client can receive multiple DHCP OFFER packets if the local network has more than one DHCP server.The client must choose between them and broadcast a DHCP REQUEST packet that identifies the explicit server and lease offer that it is accepting.
for the stored (startup) configuration
A process used to verify the identity of a person or process.
Layered Models
A model that consists of various layers that enable the development and explanation of technology to be done on a modular basis. This allows interoperability among different technologies among the different layers.
The IT industry uses layered models to describe the complex process of network communication.
A network device that has an IPv4 address assigned to it to communicate over a network.Another generic term for an end device that sends or receives messages is a host.
Application Layer Software
The functions associated with the application layer protocols in both the OSI and the TCP/IP models enable the human network to interface with the underlying data network.
Each executing program loaded on a device is referred to as a process.
Flow Control
The management of data flow between devices in a network. It is used to avoid too much data arriving before a device can handle it, causing data overflow.
Flow control can prevent the loss of segments on the network and avoid the need for retransmission.
QUESTION 36: FTP, Telnet, DNS, and SMTP are all protocols being used in the Certkiller network.Of these, which uses both TCP and UDP ports? A. TelnetB. FTPC. DNSD. SMTPE. None of the above 
Answer: C 
Explanation:  The following port numbers for the protocols listed above are as follows:FTP: TCP Port 20 and 21SMTP: TCP Port 25Telnet: TCP Port 23DNS: both TCP and UDP Port 53
A digital media file or files that are distributed over the Internet using syndication feeds, for playback on portable media players and personal computers.
1. A collision domain that is a section of a LAN that is bound by bridges, routers, or switches. 2. In a LAN using a bus topology, a segment is a continuous electrical circuit that is often connected to other such segments with repeaters. 3. When used with TCP, the term segment (verb) refers to the work TCP does to accept a large piece of data from an application and break it into smaller pieces. Again with TCP, used as a noun, segment refers to one of those smaller pieces.
Question 9
Which of the following terms defines dividing data streams into smaller pieces suitable for transmission?
C = Segmentation
Segmentation, which occurs at OSI Layer 4, is the correct answer.
P2P Networks
In a peer-to-peer network, two or more computers are connected through a network and can share resources such as printers and files without having a dedicated server.  Every connected end device, known as a peer, can function as either a server or a client.  One computer might assume the role of server for one transaction while simultaneously serve as a client  for another.  The roles of client and server are set on a per-request basis.
Unlike the client/server model, which uses dedicated servers, peer-to-peer networks decentralize the resources on a network.  Instead of locating information to be shared on dedicated servers, information can be located anywhere on any connected device.  
Interpret as Command (IAC)
In the Telnet application, commands are always introduced by a character with the decimal code 255, known as an Interpret as Command (IAC) characeter.
User Datagram Protocol (UDP)
UDP is a simple, connectionless protocol, described in RFC 768.  It has the advantage of providing low-overhead data delivery.  The segments of communication in UDP are called datagrams.  UDP sends datagrams as "best effort".
Applications that use UDP include:
Domain Name System (DNS)
Video streaming
Voice over IP (VoIP)
Only default-information originate.
What does the frame-relay status of inactive mean?
 A receiving host has failed to receive all of the segments that it should acknowledge.What can the host do to improve the reliability of this communication session? 
A. Start a new session using UDP
B. Obtain a new IP address from the DH
Answer: E 
Explanation:  A TCP window the amount of outstanding (unacknowledged by the recipient) data asender can send on a particular connection before it gets an acknowledgment back from the receiver that it has gotten some of it.For example if a pair of hosts are talking over a TCP connection that has a TCP windowsize of 64 KB (kilobytes), the sender can only send 64 KB of data and then it must stopand wait for an acknowledgment from the receiver that some or all of the data has beenreceived. If the receiver acknowledges that all the data has been received then the senderis free to send another 64 KB.One way to improve the reliability of the TCP connection is to reduce the window sizethat the receiver needs to receive before sending an acknowledgement. However, this willreduce throughput as more segments and acknowledgements will need to be sent in orderto transfer the same amount of data.
Network access devices
Connect end users to their network. Examples are hubs, switches, and wireless access points.
Internation Standards for Organization (ISO)
An international standards body that defines many networking standards. Also, the standards body that created the OSI model.
[OSI] Developed by the International Organization for Standardization (ISO) to provide a road map for nonproprietary protocol development, the OSI model did not evolve as readily as the TCP/IP model.
P2P Services and Gnutella Protocol
Many client applications are available for accessing the Gnutella network, including BearShare, Gnucleus, LimeWire, Morpheus, WinMX, and XoloX.
Many P2P applications do not use a central database to record all the files available on the peers.  Instead, the devices on the network each tell the other what files are available when queried and use the Gnutella protocol and services to support locating resources.
When a user is connected to a Gnutella service, the client applications will search or other Gnutella nodes to connect to.  these nodes handle queries for resource locations and replies to those requests.  They also govern control messages, which help the service discover other nodes.
Roles of the Transport Layer
provides transparent transfer of data between end users, providing reliable data transfer services to the upper layers.
The transport layer controls the reliability of a given link through flow control, segmentation/desegmentation, and error control.
Some protocols are state and connection oriented.
The command "frame-relay traffic-shaping" must be on the interface.
State the command to traffic-shape to 64000bps using frame-relay traffic-shaping.
QUESTION 28:Which of the protocols below use TCP at the transport layer? (Select four)A. TFTPB. SMTPC. SNMPD. FTPE. HTTPF. HTTPS

Answer: B, D, E, F Explanation: 

SMTP (Simple Mail Transfer Profile for email), FTP (File Transfer Protocol), andHTTP/HTTPS (Hyper Text Transfer Protocol for internet) all use TCP because of thereliable delivery mechanism. SMTP uses TCP port 25, FTP uses TCP ports 20 and 21,HTTP uses TCP port 80, and HTTPS uses TCP port 443.Incorrect Answers:A, C: SNMP and TFTP use UDP as the transport mechanism. Generally speaking,protocols that use the keywords "trivial" or "simple" uses UDP, since connectionless, best effort delivery mechanism usually suffice.Reference: CCNA Self-Study CCNA INTRO exam certification Guide (Cisco Press,ISBN 1-58720-094-5) Page 163. 
A complete communication process includes these steps:
1.  Creation of data at the application layer of the originating source end device
2.  Segmentation and encapsulation of data as it passes down the protocol stack in the source end device.
3.  Generation of the data onto the media at the network access layer of the stack.
4.  Transportation of the data through the internetwork, which consists of media and any intermediary devices.
5.  Reception of the data at the network access layer of the destination end device
6.  Decapsulation and reassembly of the data as it passes up the stack in the destination device.  you learn more about the encapsulation and decapsulation processes in the next section
7.  Passing this data to the destination application at the application layer of the destination end device.
Application Layer Services and Protocols
A single application can employ any different supporting application layer services.  Thus, what appears to the user as one request for a web page might, in fact, amount to dozens of individual requests.  For each request, multiple processes can be executed.  For example, the FTP requires a client to initiate a control process and a data stream process to a server.
Additionally, servers typically have multiple clients requesting information at the same time.  A Telnet server can have many clients requesting connections to it.  These individual client requests must be handled simultaneously and separately for the network to succeed.  The application layer processes and services rely on support from lower-layer functions to successfully manage the multiple conversations.
Changes you make in config mode are stored
in the RAM, running-config
Name the different ways to configure IPv6
Stateful autoconfiguration, assigns a complete 128 bit address.Stateless autoconfiguration, gives out the prefix and the EUI is added.EUI-64, prefix is determined by the administrator, and the last 64bits with the EUI mechanism.
Getting Data to the Right Application
At Layer 4, information contained in the PDU header does not identify a destination host or a destination network.  What it does identify is the specific process or service running on the destination host device that will act on the data being delivered.
A user can send and receive many types of traffic over a single network interface, and using port numbers for each segment keeps traffic for web pages separate from em-mail traffic and so on.  The segment contains both source and destination ports in case the receiver needs to contact the sender.
Basic interface configurations Interface fa 0/1 (fastethernet 0/1) (Configuration commands that follow apply JUST to fa 0/1)
Config t is how to get into the basic interface modeDescription Host-A Speed 100Duplex FullShutdown (NOTE –default is switch ports are up)No Shutdown
In PIM-SM this always points to the RP.
What is a (S,G) entry?
9.  The Linux and UNIX operating systems use SAMBA, which is a version of which protocol?
A.  The Linux and UNIX operating systems provide a method of sharing resources with Microsoft networks using a version of SMB called SAMBA. - To inform all routers that it wants to leave.
Solicited Membership Reports are sent to what address?
Application layer in OSI and TCP/IP Models
The application layer, Layer 7, is the top layer of both the OSI and TCP/IP models.  Layer 7 provides the interface between the applications you use to communicate and the underlying network over which your messages are transmitted.  
What happens if you issue a "clear ip route *" when using EIGRP?
The routing table is repopulated through the EIGRP topology table. It will not change what paths it choose in the first place. No queries are sent, and no routes go active.
QUESTION 20:Which of the following correctly describe steps in the OSI data encapsulationprocess? (Choose two)A. The presentation layer translates bits into voltages for transmission across the physicallink.B. The transport layer divides a data stream int
Answer: B, C   Explanation:  The Transport Layer: You can think of the transport layer of the OSI model as a boundary between the upper and lower protocols. The transport layer provides a data transport service that shields the upper layers from transport implementation issues such as the reliability of a connection. The transport layer provides mechanisms for: Segmenting upper layer application The establishment, maintenance, and orderly termination of virtual circuits information flow control and reliability via TCP Transport fault detection and recovery  The Network Layer: Layer three of the OSI model is the network layer. The network layer creates and sends packets from source network to destination  network. it provides consistent end-to-end packet delivery service and control information it creates and uses layer3 addresses for use in path determination and to forward  packets. Incorrect Answers: A: This correctly describes the physical layer, not the presentation layer. D: Although the data link layer adds physical (MAC) source and destination addresses, it adds it to a frame, not a segment. E: Packets are encapsulated, not frames.
The address 01005e is always used in the mac-address as the first 24 bits. That leaves 24 bits for the rest of the MAC address.The lowest 23 bits are mapped directly into this, and 0 is the 24th bit. IP multicast addresses always start with 1110 (224). Th
The reason behind this, is that all multicast addresses start with 1110, that leaves 28 bits. Since we only map the lower 23 bits, we have 5 bits remaining (2^5 = 32).
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