Network Management (3.1 & 3.2) Flashcards
Network Management
o The process of administering and managing computer networks
Physical Network Diagram
▪ Shows the actual physical arrangement of the components that make up
the network
Logical Network Diagram
▪ Illustrates the flow of data across a network and shows how devices
communicate with each other
Wiring Diagram
▪ Labels which cables are connected to which ports
Radio Frequency (Wireless) Site Survey
▪ Planning and designing a wireless network to deliver the required
wireless solution
Wired Site Survey
▪ Determines if a site has the right amount of power, space, and cooling to
support a new upgrade or installation
Audit and Assessment Report
▪ Delivered after a formal assessment has been conducted ● Audit and Assessment Report o Executive summary o Scope and objectives o Assumptions and limitations o Methods and tools o Environment and system diagram o Security requirements o Findings and recommendations o Audit results
Baseline Configurations
▪ Set of specifications for an information system, or a configuration item
within a system, that has been formally reviewed and agreed on
▪ Changes will be properly tested and approved to be part of the new
baseline
Network Performance Monitoring
Monitors the performance from the end user’s workstation to the final
destination they are trying to reach
Latency
o Time that it takes for data to reach its destination across a
network
o High latency slows down overall network performance
Bandwidth
o Maximum rate of data transfer across a given network
Throughput
o Actual measure of how much data is successfully
transferred from the source to a destination
Jitter
o When a time delay in the sending of data packets over a
network connection occurs
▪ Ensure that your network is using QoS properly
Sensors
o Monitors a device’s temperature, CPU usage, and memory, which could indicate if it is operating properly or is about to fail o Minor Temperature Threshold ▪ Used to set off an alarm when a rise in temperature is detected but hasn’t reached dangerous levels yet o Major Temperature Threshold ▪ Used to set off an alarm when temperature reaches dangerous conditions ● 5-40% CPU utilization o Misconfigured network o Network under attack ▪ Minor ▪ Severe ▪ Critical ● 40% o Normal conditions ● 60-70% o Busier times ● Layer 3 80% o Peak times
Full Packet Capture is used to
o capture the entire packet, including the header
and the payload for all traffic entering and leaving a network
Flow Analysis
▪ Relies on a flow collector to record the metadata and statistics about
network traffic rather than recording each frame
▪ Highlights trends and patterns
NetFlow
▪ Defines a particular traffic flow based on the different packets that share the same characteristics ● Protocol interface ● IP version/type ● Source/destination IP ● Source/destination port ● IP service type
Zeek
▪ Passively monitors a network like a sniffer, but only logs full packet
capture data of potential interest
▪ Performs normalization of the data and stores it as a tab-delimited or
JSON-formatted text files
Multi Router Traffic Grapher (MRTG)
▪ Creates graphs showing traffic flows through the network interfaces of
routers and switches by polling the appliances using SNMP
Link State
▪ Communicates whether a given interface has a cable connected to it and
a valid protocol to use for communication
Drop
▪ Used to count the number of packets that have been dropped
Flush
▪ Used to count Selective Packet Discards (SPD) that have occurred
Selective Packet Discards (SPD)
▪ Drops low priority packets when the CPU is too busy so it can save
capacity for higher priority packets as a form of QoS
Runt
▪ An Ethernet frame that is less than 64 bytes in size
Giant
▪ Any Ethernet frame that exceeds the 802.3 frame size of 1518 bytes
Throttle
▪ Occurs when the interface fails to buffer the incoming packets
CRC
▪ Number of packets received that failed the cyclic redundancy checksum,
or CRC check upon receipt
Frame
▪ Used to count the number of packets where a CRC error and a non integer number of octets was received
Overrun
▪ Used to count how often the interface was unable to receive traffic due
to an insufficient hardware buffer
Ignored
▪ Used to count the number of packets that the interface ignored since the
hardware interface was low on internal buffers
Underrun
▪ Number of times the sender has operated faster than the router can
handle, causing buffers or dropped packets
Babble
▪ Used to count any frames that are transmitted and are larger than 1518
bytes
Late Collision
▪ Used to count the number of collisions that occur after the interface has
started transmitting its frame
Deferred
▪ Used to count the number of frames that were transmitted successfully
after waiting because the media was busy
Output Buffer Failure
▪ Number of times a packet was not output from the output hold queue
because of a shortage of shared memory
Output Buffer Swapped Out
▪ Number of packets stored in main memory when the queue is full
Environmental Sensors
o Environmental monitoring ▪ Network devices operate between 50 and 90 ºF ▪ Maintain a humidity range of 40-60% ● Cool ● At the right humidity ● Receives clean power ● Flood-free
