Network Operations Flashcards
Device/Chassis sensors
Abnormal values can signal a problem
Bandwidth
Amount of network use over time.
Excessive bandwidth could signal lack of available space, etc.
Latency
A delay between request and response.
High latency signals a problem.
Jitter
The time between frames. Excessive jitter can cause choppy calls/video.
SNMP
Simple Network Management Protocol.
On a network, devices run an SNMP Agent that responds to queries (or just sends information to) from an SNMP Manager (a server).
SNMP Traps
SNMP OIDs
Object Identifiers. Statistics about devices, example: How many bytes have gone into a router interface?
SNMP MIBs
Management Information Bases. A database of information that you can query for info (MIB II). Some proprietary MIBs also exist.
Syslog
Message logging protocol that creates a consolidated log. Stored in a central logging receiver (SIEM)
Logging Levels/Severity Levels
- Emergency
- Critical
- Major
- Minor
- Warning
- Notice
- Info
- Trace
- Debug
Speed/Duplex
Must match on both ends of a link.
CRC errors
Typically caused by bad cable or interface.
Giants
Frames that are more than 1518 bytes (when not using jumbo frames). Can indicate a communication problem.
Runts
Frames that are less than 64 bytes - can be the result of a collision.
Encapsulation Errors
Mismatch between switch tagging configurations (ISL / 801.2Q)
Netflow Data
Gathers traffic statistics from all traffic flows. Consists of a probe and a collector. The probe collects data and sends it to the collector.
Change Management
Clear policies to document a change to a device/ configuration, etc.
Incident Response Plan
How to respond to security incidents:
Preparation
Detection/Analysis
Containment, Eradication, and Recovery
Post-Incident Activity
Disaster Recovery Plan
How to keep things going after/during a disaster.
Business Continuity Plan
Can involve manual/physical methods of doing things instead of using a computer
System Life Cycle
Must include managing asset disposal (can data be kept? should it be kept? how to make sure it can’t be stolen)
AUP
Acceptable Use Policy
Determines what is the acceptable use of company assets (Internet, telephones, computers, mobile devices). Used to limit legal liability
DLP
Data Loss Prevention looks for sensitive data and blocks it from leaving the company network.
Floor Plans
Overlays the wired and wireless network with existing architectural layout.
Can also be useful for patch panel labels to associate a desk with a number.
Physical Network Map
Shows how each physical device is connected to the others (physical wires and devices). Can include rack locations.
Distribution frame
Passive cable termination with punch down blocks or patch panels.
MDF
Main Distribution Frame - central point of the network; termination point for WAN links.
IDF
Intermediate Distribution Frame - an extension of the MDF (for places with multiple floors, etc.)
Logical Network maps
Gives you an overall view of connectivity for an organization. Shows WAN layout, application flows, etc.
Site Survey
Samples wireless landscape of an area. Allows you to configure WAPs to avoid interference.
Cold Site
(Recovery site) An empty building; no data, no hardware, no people, etc.
Hot Site
An exact copy of your existing data center. Automated replication of data. Duplicate hardware, etc.
Warm Site
Just enough to get going in event of a disaster.
Cloud Site
Some cloud providers can provide resources for recovery processes.
Active-passive redundancy
Two devices are installed and configured, but only one is operating at a time.
Active-Active redundancy
Both devices are active at the same time.
Diverse paths
Creating multiple paths for data to follow (example: more than one ISP)
FHRP
First Hop Redundancy Protocol. Allows a router to take over as the default gateway if the default one fails.
VRRP
Virtual Router Redundancy Protocol. The “default” router is a virtual machine.
RTO
Recovery Time Objective. How long until it’s up and running
RPO
Recovery Point Objective. How much data loss is acceptable, etc.
Full backup
All files are backed up
Differential backup
All files that have changed since the last FULL BACKUP are backed up.
Incremental backup
All files that have changed since the last INCREMENTAL BACKUP are backed up. Leads to longer recovery times since the data must be reconstituted from the full backup + all incremental backups.
Protocol analyzer
A tool used to analyze traffic in a network. It allows you to view frame contents.
