click below
click below
Normal Size Small Size show me how
Cisco CCNA
Flash cards for Cisco CCNA exam
Question | Answer |
---|---|
Ethernet supports the following topologies | Physical bus, logical bus Physical star, logical bus Physical star, logical star |
CSMA/CD | Carrier Sense, Multiple Access/Collision Detection |
Most common transmission medium used for Ethernet | Unshielded twisted-pair cables (UTP) with RJ-45 connectors |
Cat3 | Rated Up to 10 Mbps |
Cat4 | Rated Up to 16 Mbps |
Cat5 | Rated Up to 100 Mbps |
Cat5e | Rated Up to 1000 Mbps (Gigabit) |
ST, SC, LC, and MT-RJ | Fiber Optic Connectors |
thinnet or thicknet | Coaxial |
12-digit hexadecimal number (each number ranges from 0-9 or A-F) | Mac Address |
10Base2, 10Base5, 10BaseT | Ethernet Standards |
100BaseTx,100BaseT4,100BaseFx | Fast Ethernet Standards |
Fast Ethernet Bandwidth | 100 Mbps Half Duplex, 200 Mbps Full |
1000BaseSX Distance | 220 to 550 meters |
1000BaseLX Distance | 550 to 5,000 meters |
Cable standard for Twisted pair (Cat5e) | 1000BaseT |
Collision detection is turned on The device can only send or receive at any given time Devices connected to a hub must use half-duplex communication | Half Duplex |
Collision detection is turned off The device can send and receive at the same time Requires full-duplex capable NICs Requires switches with dedicated switch ports (a single device per port) | Full Duplex |
Encapsulation | The process of breaking a message into packets, adding control and other information, and transmitting the message through the transmission media |
Used to get the MAC address of a host from a known IP address | ARP |
Used to discover the IP address of a device with a known MAC address | BootP, RARP |
Route discovery protocol that uses the link-state method | OSFP (Open Shortest Path First) |
Route discovery protocol that uses the distance-vector method | RIP (Routing Information Protocol) |
Process layer | TCP/IP Suite layer also called the Application Layer |
connects two media segments that use the same protocol | Bridge |
80/20 Rule | At least 80% of network traffic should stay within a segment. No more than 20% of network traffic should pass through the bridge to another segment. |
Device used to isolate traffic to a segment | Bridge |
A multiport bridge | Switch |
Devices that connect multiple segments or devices and forward packets to only one specific port | Switches |
If the destination address is not in the database, the packet is sent out all ports except for the one on which it was received. | Flooding |
Store-and-forward | Receive the entire frame. Verify the frame's integrity (check the CRC). Frames with errors are not forwarded. Forward the frame to the destination device. Introduce more latency (delay) than cut-through switches. |
Cut-through | Read the destination device address. Forward the packet without verifying frame integrity. Are faster than store-and-forward switches (less latency). |
Fragment-free | Read the first 64 bytes of a frame. Verify that the packet is not a fragment. Forward non-fragmented frames. Introduce some latency, but not as great as store-and-forward switching. |
A device that sends packets from one network to another network | Router |
7 Layers of the OSI Model | Physical, Data Link, Network, Transport, Session, Presentation, Application |
Benefits of the OSI Model | Reduces Complexity Standardizes Interfaces Facilitates Modular Engineering Ensures Interoperable technology Improves troubleshooting ability |
Physical Layer of the OSI Model | Binary Transmission. Defines the electrical, mechanical, procedural and functional specifications for activating, maintaining and deactivating the physical link. |
Data Link Layer of the OSI Model | Also called the framing layer. Takes upper layer data and turns it into frames and allows it to acces the media. Defines how data is formatted for transmission and how access to the network is controlled. -Provides error detection |
Network Layer | -Data Delivery - Deliver data packets that are actually routed between systems. -Selects the best path to deliver data -Provides logical addressing and path selection |
Transport Layer | -Allows reliable data transport to occur. -Handles transportation issues between hosts -Establishes, maintains and terminates virtual circuits -Provides reliability through fault detection and recovery information flow control |
Session Layer | -Interhost Communication - Establishes, manages and terminates sessions between applications. -Makes sure a session is properly established |
Presentation Layer | Data Representation -Designed to represent data itself to the application -Ensures data is readable by the receiving system -Formats data -Structures data -Negotiates data transfer syntax for the application layer -Provides encryption |
Application Layer | Network process to applications -Process data for the application -Provides network resources to application processes such as electronic mail, file transfer and terminal emulation -Provides user authentication |
FCS | Frame Check System (Also known as CRC) - placed during the framing process at the Data Link layer and is a mathematical computation of all the information in the frame. Used for error checking. |
Datagrams | Seen at the Application, Presentation and Session layer |
Segments | Formed at the Transport layer |
Packets | Formed at the network layer |
Frames | Formed at the Data Link level |
Bits | Bits reside at the physical level of the OSI model |
TCP/IP Model | Application (Process) Host-to-Host Internet Network Access (can be broken into 2 pieces) |
ARP | Maps IP addresses to BIA (Burned in Addresses) mac addresses |
RARP | Maps Mac addresses to IP addresses |
IP protocol | Operates at layer 3 of the OSI model Connectionless Packet treated independently Hierarchal Addressing scheme Uses best effort delivery |
UDP Protocol | Operates at the transport layer Provides sockets based connectivity with connection limitations Connectionless protocol Limited error checking Uses best effort delivery No recovery features |
TCP Protocol | Operates at the transport layer Connection oriented (session established prior to sending data) Full duplex mode Provides error checking Acknowledgement of receipt Data recovery features Uses three way handshake |
DHCP Operation Messages | Discover (BootP, RARP broadcast) Offer Request Acknowledge |
EIA-232-D | Defines Asynchronous serial connections - OSI Layer 1 |
HDLC | Specifies encapsulation for synchronous data links using bit-oriented framing - OSI Layer 2 |
PPP | Provides synchronous and asynchronous point to point connections -OSI Layer 2 |
ISDN | Communication protocols that allow telephone networks to carry voice, data,graphics, music and video - OSI Layer 1-3 |
T568A Pinouts | 1. G/W 2. Green 3. Orange/W 4. Blue 5. Blue/W 6. Orange 7. Brown/W 8. Brown |
T568B Pinouts | 1. Orange/W 2. Orange 3. GR/W 4. Blue 5. Blue/W 6. Green 7. Brown/W 8. Brown |
What pins do switches use to send data? | 3 and 6 |
What pins do nics use to send data? | 1 and 2 |
Used when the pins on each endpoint use different pins to send and receive data | Straight-through cable |
How many bits in a mac address? | 48 bits |
How many bits in the OUI of the Mac address | 22 bits |
How many bits are in the Vendor assigned portion of the Mac address? | 24 bits |
What makes up the structure of a frame? | Preamble Destination Mac Address Source Mac Address Length/Type Header/Data FCS |
How many bytes are in the data portion of a frame? | 46-1500 bytes |
How many bytes in the preamble portion of a ethernet frame? | 8 bytes |
How many bytes in the preamble portion of a 802.3 frame? | 7 bytes for preamble, 1 byte for SOF (start of frame) |
How many bytes in the FCS portion of a frame? | 4 bytes |
How many bytes in a frame? | 1518 or 1514 without the FCS |
What is the first address in a frame? | Destination address |
How many bytes in the source and destination mac address for a frame | 6 bytes each |
What are the three different ways to communicate within a network? | unicast (1 station to another) broadcast (communicate with all systems on a particular segment) multicast (build applications to advertise directly to a client group or socket) |
Base 2 number system | binary numbers 1's and 0's |
How many bits are in a 1 byte? | 8 |
What layers of the OSI model do WAN technologies run on? | Layers 1 and 2 |
Name three WAN Networking devices | ATM Switches Frame Relay Switches ISDN/PSTN Switches |
WAN Technologies are based on what type of communication? | Serial Communication |
What is DTE? | Data Terminal Equipment - User device with interface connecting to the WAN link. |
What is DCE? | Data-Circuit Terminating Equipment - End of the WAN provider side of the communication facility. |
What type of connection is made between DCE and DTE points? | Primarily EIA/TIA-232 (RS232) but can also use V.35 , X.21 and HSSI |
Name an example of DTE. | CSU/DSU |
Name Data-Link Protocols | ATM PPP HDLC LAPF (Frame Relay) LAPD (ISDN2) |
What are the two WAN link options | Dedicated (Leased lines such as T1,T3,E1,E3)0 Switched (circuit switched, packet switched, cell switched) |
What is the available bandwidth for a T1 leased line? | 1.544 Mbps |
What is the available bandwidth for a T3 leased line? | 43.7 Mbps |
What is DS0? | A phone company standard - digital signal type 0 and equals 65 kb in size |
How many DS0's in a T1, T3 | 24 DS0 in a T1 (last DS0 used for framing) 672 DS0 in a T3 |
What is the frame structure of HDLC? | Flag | Address | Control | Data | FCS | Flag |
What is the frame structure of Cisco HDLC? | Flag | Address | Control | Proprietary | Data | FCS | Flag |
What is the difference between the industry standard HDLC and Cisco's proprietary HDLC? | Cisco HDLC allows for simultaneous multiplexing of layer 3 protocols. |
What is the default serial connection on all Cisco routers? | HDLC |
What is PPP? | Industry standard for encapsulation that includes authentication, link level compression, multiple layer 3 multiplexing and callback |
Point to point connection advantages | Simplicity Quality Availability |
Point to point connection disadvantages | Cost Limited Flexibility |
What is the maximum yield of a single DS0? | 56 Kbps |
How many DS0's in a ISDN? | 3 DS0 (1 used for the framing) |
What is the D channel? | The 24th DS0 channel used for framing |
DLCI | Data Link Connection Identifier (used with Frame Relay) |
What is VCI? | Virtual Circuit Identifier (used in Cell switching with ATM) |
What is PAT? | Port Address Translation - translates the local computer's IP address to the access router's public IP address. |
What is NAT? | Network Address Translation without the translation of ports. |
What is the 5 4 3 rule? | Can not have more than 5 segments with 4 repeaters and 3 segments populated |
What is microsegmentation? | Dedicated paths between sender and receiver hosts |
In the Hierarchy of design, what is the Core Layer? | Provides optimal transport between core routers and distribution sites |
In the Hierarchy of design, what is the Distribution Layer? | Provides Policy-based connectivity, peer reduction, and aggregation. |
In the Hierarchy of design, what is the Access Layer? | Provides common group access to the internetworking environment. |
What is the 5 4 3 rule? | Can not have more than 5 segments with 4 repeaters and 3 segments populated |
What is microsegmentation? | Dedicated paths between sender and receiver hosts |
In the Hierarchy of design, what is the Core Layer? | Provides optimal transport between core routers and distribution sites |
In the Hierarchy of design, what is the Distribution Layer? | Provides Policy-based connectivity, peer reduction, and aggregation. |
In the Hierarchy of design, what is the Access Layer? | Provides common group access to the internetworking environment. |
What are the parts of the UDP header? | Source Port (16 bit) Destination Port (16 bit) UDP Length (16 bit) UDP checksum (16 bit) Data (level 5-7 data) |
What is the three way handshake for TCP? | Syn Syn/Ack Ack |
What flag indicates the very last packet in a TCP session? | Fin |
What is the standard network management method that leads to consistent and predictable data flow across the network? | Qos (Quality of Service) |
What is the network management tool that manages latency, jitter and packet loss and provides priority and dedicated bandwidth? | Qos (Quality of Service) |
What is the address range for a class A IP address? | 1-127 |
What is the address range for a class B IP address? | 128-191 |
What is the address range for a class C IP address? | 192-223 |
What is it called when all hosts in a given network scheme will always use the same subnet mask to provide exact routing. | classful subnetting |
What metrics are used for routing? | Bandwidth, delay, hop count, cost |
What is the function of distance vector routing protocols? | Passes periodic copies of the entire routing table to neighbors, which accumulate distance vectors |
What is the function of a link state protocol? | After the initial synchronization of routers, small, event triggered link state updates are passed between neighbors. |
In routing, what is the administrative distance number for RIP? | 120 |
In routing, what is the administrative distance number for EIGRP? | 90 |
In routing, what is the administrative distance number for OSPF? | 110 |
In routing, what is the administrative distance number for IS-IS? | 115 |