CCNA 1 to 20 Flashcards
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MDF
Main distribution facility
Stackable Switch
Single unit, that is one U in size, is managed by itself. (Full rack is usually 42 U in size)
Stack Wise Cable
Combines multiple switches into one single brain that can be managed. Cisco proprietary name.
Flash Memory
Stores a compressed version of the IOS in the memory. When you boot, the IOS is decompressed to dynamic memory.
Flash= non volatile
Dynamic Memory= volatile
Dynamic Memory
volatile memory, erases after reboot.
Layer 2 Switch
At layer 2 of the osi model- learns MAC addresses and stores them in a Cam Table- content addressable memory.
Layer 3 Switch
At Layer 3 of the osi model - does routing in the hardware using ASIC. ( routers use software and are slower but have more features , where as switches use hardware- faster but less features)
Application specific integration circuitry (ASIC)
Allows the switch to see information like MAC address and take action on that information just as fast as the cable is able to transmit information.
Forward
Happens when the switch knows where the destination device is located. Sends the packet to that specific port.
Frame
Layer two communication, when data leave layer two, it is called a packet:
[Header(FCS) + Data+ TCP/UDO Ports+ SRC IP+ DST IP + SRC MAC address + DST Mac Address ]
Smartnet
Cisco website that gives information regarding devices, i.e memory and compatible IOS
SFP ports
Small Form Pluggable transceiver - moreable modules, commonly, you will see fiber cables as there are many different types of these cables.
Switch to switch communication, long distance using fiber.
Supervisor Engine
the brain of a chassis based switch.
IOS
internetwork operating system
Cisco firmware
Single Wide
Common size modules/ 1/2 width. Usually carrier module for VICs and WICs
Prolific chipset serial connection
Supports sending a break signal over a usb to serial connection.
VIC
Voice Interface Card:
Allows POTs to communicate on your router/ switch
WEP (wired equivalent privacy )
when wireless first was created the first real type of security that was used.
Wireless Access Point
- Layer 2 device
- Communicate Data packets (Frames) wirelessly over the 2.4 GHZ and 5 GHZ radio frequencies.
- Transmission is done over RF ( Radio frequency ) channels-represents a part of the RF.
- latest standard is 802.11AX AKA WI-FI 6
- In the 2.4 GHz band, 1, 6, and 11 are the only non-overlapping channels
Broadcast Domain
a logical division of a computer network (VLANS), in which all devices can reach each other bybroadcastat the data link layer (Layer 2). Abroadcast domaincan be within the same LAN segment or it can be bridged to other LAN segments.
Communication sent on ff:ff:ff:ff:ff:ff
How far a broadcast will go on a logical connection
ex. logical division = VLANs
WIC
WAN Interface Card—
“WIC” is a type of specialized network interface controller card (NIC) made by Cisco that allows a network device such as a router to connect and transmit data over a Wide Area Network
Collision Domain
a network segment connected by a shared medium or through repeaters where simultaneous data transmissions collide with one another. Thecollision domainapplies particularly in wireless networks, but also affected early versions of ethernet
ICMP
Internet Control Message Protocol:
is an internet layer protocol used by network devices to diagnose network communication issues. ICMP is mainly used to determine whether or not data is reaching its intended destination in a timely manner. Commonly, the ICMP protocol is used on network devices, such as routers.
Ping uses ICMP.
Metropolitan Ethernet connection
Direct connection between two points that are physically faraway from each other.
Connects your site with ethernet
The ethernet is usually running over a different topology
- Pure Ethernet
- Ethernet over SDH
- Ethernet over MPLS
- Ethernet over DWDM
Multi Mode Optical Fiber
used to transmit multiple signals per fiber they have larger cores and are used for short distance transmits. Core is made of plastic, multi mode can travel… ?
Single Mode
used to transmit one signal per fiber. Transmit further than multi mode. Used to transmit over large distances.
Unicast
is communication between a single sender and a single receiver over a network.
PoE/ PoE +
PoE/ PoE +
Cisco Inline Power 2001/02
802.3AF- 2003 15.4 W
(uses pulse to determine power, either on or off)
–> mode A uses pin’s 1,2,3,6
–> mode B uses pin’s 4,5,7,8
| 802.3AT- 2009 (POE+) 30 W
|
| 802.3BT- TYPE 3 (4 PPOE) 60 W
| 802.3BT- TYPE 4 100 W
|
\ \_\_ [used LLDP to regulate power ]
[ Backwards compatible ]
Runt
a runt is a packet that is too small. For example, the Ethernet protocol requires that each packet be at least 64 bytes long, a runt is smaller than 64 bytes.
Giant
A giant frame is any frame whose size exceeds the maximum transmission unit (MTU). In ethernet thats larger than 1500bytes
Common TCP/ UDP Ports
Common TCP/ UDP Ports
- 25 - SMTP
- 22 SSH
- 80 HTTP
- 23 Telnet
- 443 Https
Router
Router: “Network wall” divides up network spaces contained in one area.
The primary function of a router is to control broadcast and forward directed data packets between networks:
- contain network chatter
- Relies on IP based routing tables
- Acts as a gateway between network types
Passive PoE
Passive PoE, also known as the passive Power over Ethernet, is a non-standard PoE. It can also deliver power over the Ethernet lines, but without the negotiation or communication process. Passive PoE switch does not adhere to any IEEE standard. The power is “always-on” when using passive PoE switch in networks, which means it always sends electric current out over the Ethernet cable at a certain voltage regardless of whether the terminal device supports PoE or not. So using passive PoE switch may burn out the terminal devices if they’re not prepared for electrified Ethernet cables.
Active PoE
Active PoE, short for active Power over Ethernet, is also known as standard PoE which refers to any type of PoE that negotiates the proper voltage between the power supply equipment (PSE) and the PD device. Active PoE switch is a device that complies with standard PoE, so it is also named standard PoE switch.
IPv4 Address Classes
IPv4 Address Classes RFC 1918
Class ——— Range——————————- Subnet Mask
A———– 0-127.255.255.255——————– 255.0.0.0
B———– 128-191.255.255.255—————— 255.255.0.0
C———– 192-223.255.255.255—————– 255.255.255.0
D———– 224 -239.255.255.255—————- Multicast
E ———- 240- 255.255.255.255————— Experimental Research
** Subnet Mask show are classfull**
Classfull Mask v Classless Mask
Classfull Mask v Classless Mask
Classfull Mask use the full range of an IP class
Classless Mask allows to change the subnet mask and allows the use or a smaller IP range.
Hub
a hub is the most basic networking device that connects multiple computers or other network devices together. Unlike a network switch or router, a network hub has no routing tables or intelligence on where to send information and broadcasts all network data across each connection.
DSP
Digital Signal Processor
Break up and process voice
enables Cisco Integrated Services Routers to provide high-density voice connectivity, conferencing, and transcoding capabilities in Cisco IP Communications solutions
ARP
Address Resolution Protocol:
a network layer protocol used to convert an IP address into a physical address.
Dynamic Port Number
dynamic or private port numbers are 49152 through 65535. These ports are not registered TCP or UDP ports with IANA/ the Internet Assigned Numbers Authority
EtherChannel (LAG)
An EtherChannel or Link Aggregation Group is used to bundle several physical links into a single logical link. This is commonly used between switches, and from large physical hosts to a switch.
Ex, between two different buildings/ location in a layer two network.
OSI Model
7- Application
- Endusers interact with w/ network communication
- houses all the network aware applications
6- Presentation
- How should data be presented from the Application layer ( data encryption )
- ensures that data is in a usable format and is where data encryption occurs
5- Session
- Maintains connection and is responsible for controlling ports and sessions
4- Transport
- Establish logical end to end communication
- transmit data using transmission protocols (Tcp, UDP)
3- Network
- What valid paths exist and what paths the data will take.
- basically what protocol is being use and the port that is being used for the source and designation. The IP address of the source and the IP of the destination.
2- Data Link
- Switch, ,main layer ( Mac addresses )
- the path it needs to take to get to the destination from current location (by MAC address and IP address)
1- Physical
- Anything dealing with network cables or the standards in use including the ponds, connectors, and the electric current used.
TCP/ IP Model
4- Application Layer
- Endusers interact with w/ network communication
- How should data be presented from the Application layer ( data encryption
- Maintains connection and is responsible for controlling ports and sessions
3- Transport Layer
- Establish logical end to end communication
- transmit data using transmission protocols (Tcp, UDP)
2- Internet Layer
- basically what protocol is being use and the port that is being used for the source and designation. The IP address of the source and the IP of the destination.
1- Network Access layer
- Switch, ,main layer ( Mac addresses )
- the path it needs to take to get to the destination from current location (by MAC address and IP address)
- Anything dealing with network cables or the standards in use including the ponds, connectors, and the electric current used.
What makes up a fiber cable?
Fiber = Core+ cladding + Buffer(+Jacket)
- Core: Glass, used to send the light signal that represents the network signal - Cladding: Glass, makes sure that the light stays inside of the cable - Buffer AKA Jacket: Plastic shielding
How is a fiber cable measured?
- Fiber diameter measured in Microns (Millionth of a meter) usually displayed in Core + Cladding. (Core/cladding)
- Most fiber is 125 microns
- Multimode is typically 50/125 (Thicker)
- Single mode is typically 9/125
Patch Panel
hardware assembly that contains ports used to connect and manage incoming and outgoing LAN cables
Two-Tier (collapse core)
- Definition: this design is meant to maximize performance and user availability to the network, while still allowing for design scalability over time. In this type of architecture the distribution layer is merged with the core layer.
- Tier 2: Distribution/core - important critical items.
- Tier 1: Access - everything that needs to be plug in or access the network
Three-Tier
- Definition: “hierarchical model can help you design, implement, and maintain a scalable, reliable, cost-effective hierarchical internetwork. Cisco defines three layers of hierarchy, the core, distribution, and access, each with specific functions, and it’s referred to as a 3-tier network architecture.”
- Tier 3: Core
- Tier 2: distribution
- Tier 1 : Access
Spine Leaf Architecture
Normally used at data centers
spine and leaf (leaf spine) is a two-layer network topology composed of leaf switches and spine switches. … Leaf switches mesh into the spine, forming the access layer that delivers network connection points for servers.
- Spine is a backbone-only, servers connected to the leaf
- Connections everywhere-full mesh between spine and leaf
- Goal: Lightning-fast east-west traffic flow; combine traffic
▢ ▢ Spine | \ /| | \ / | | / \ | ▢ ▢ Leaf
All Spines are connected to all leafs, though there is no connection between spines. Because all spines are connected to all leafs, this allows for load balancing between connected spines.
Plenum cable
designed to be in the ceiling space above the rack, these cables are fire resistance.
These spaces normally share with HVAC.
Riser cable
are used in spaces that do not intermingle with normal air circulation, not fire resistant.
WAN
WAN- Wide Area Network
Connecting businesses to businesses though private connections
either
“leases lines”= T1 or E1 line
-> one to one connection
or :MPLS or Metro E”= packet switch network
–>connections can be built though virtual circuits (normally cheaper)
or
–VPN
Metro E
Metropolitan Ethernet Connection
Fiber connection between metro areas leased from your ISP
“leases lines”= T1 or E1 line
Metro E can connect across state if your ISP has the reach/ is available in both location .
VPN
Virtual Private network, essentially a private WAN ran over the Internet to connect different physical locations to the same network.
PSTN v MPLS
PSTN v MPLS
Public Switched Telephone Network—
The analog telephone system. We use PSTN whenever we pick up our cellphones or house phone to make a call. The analog signal is converted into a digital signal to allow it to travel a long distance and it then translated back to analog when our phones receive them (POTS). PSTN today also has the capability to transmit data.
v.
Multiprotocol Label Switching (MPLS) is a packet forwarding technology that uses label to make decisions rather than long network addresses, thus avoiding complex lookups in a routing table and speeding traffic flows.
SOHO
SOHO network or also termed as single or small office/home office network is mainly referred to a business category involving a small number of workers
DAC Cable
Direct attach connection cable (DAC).
It is an SFP and the cable bonded together directly from the factory. Usually for items that are in the same rack.
They have Fiber and coper cables.
HSRP v VRRP
Allows two interfaces to act as one, helpful for failover
Hot Standby Router Protocol (HSRP) is a CISCO proprietary protocol, which provides redundancy for a local subnet. In HSRP, two or more routers gives an illusion of a virtual router. HSRP allows you to configure two or more routers as standby routers and only a single router as active router at a time.
V.
The Virtual Router Redundancy Protocol (VRRP) is a computer networking protocol that provides for automatic assignment of available Internet Protocol (IP) routers to participating hosts. This increases the availability and reliability of routing paths via automatic default gateway selections on an IP subnetwork.
Allows for Active Standby**
Com Port
An Asynchronous port on the computer used to connect a serial device to the computer and capable of transmitting one bit at a time. Serial ports are typically identified on computers as COM (communications) ports. For example, a mouse might be connected to COM1 and a modem to COM2
Command: Show CDP neighbors
CDP- Cisco discovery protocol.
This shows what Cisco devices the current device are connected to.
LLDP
Link Layer Discovery Protocol: link layer protocol used by network devices for advertising their identity, capabilities, and neighbors on a local area network
How long does a Cisco switch remember a dynamically learned MAC address, by default?
300 sec or 5mins
What are the two manger Copper cable Standards? (Patch panels/ jacks)
T-568A and T-568B
Straight through cable
A straight through cable is a type of twisted pair cable that is used in local area networks to connect a computer to a network hub such as a router. This type of cable is also sometimes called a patch cable and is an alternative to wireless connections where one or more computers access a router through a wireless signal. On a straight through cable, the wired pins match. Straight through cable use one wiring standard: both ends use T568A wiring standard or both ends use T568B wiring standard..
Cross over cable
When you have T-568A or T-568B on opposite sides. This cable is usually used for connecting two devices of the same type together.
MDI-X Standard
(medium dependent interface) - Auto MDI-X ports on newer network interfaces detect if the connection would require a crossover, and automatically chooses the MDI or MDI-X configuration to properly match the other end of the link.
What is the Maximum cable length that can be used before encountering packet loss?
100 Meters
Private Addresses
Class A: 10.0.0.0
Class B: 172.16.0.0 - 172.31.0.0
Class C: 192.168
Private Addresses will not work on the internet without NAT
ISE
Cisco Identity Services Engine (ISE) enables a dynamic and automated approach to policy enforcement that simplifies the delivery of highly secure network
Can be used as an AAA server (for example)
