Troubleshoot Guides

Alex's Second Brain

Cooking
cron
GRUB2
Digital Audio Workstation (DAW)
Renoise
Electronic Dance Music (EDM)
RHCSA
Pacemaker
Data Compression
AWS Networking
DevOps
RPM Package Manager
Unix and Linux System Administration Handbook
Ansible
Network Topologies
Server Message Block
Name Servers
Name Spaces
Hosts
NetBIOS
Network Naming
SSH
Routing Protocol
Routing table
Routing
Internet Engineering Task Force
Subnetting
Classless Inter-Domain Routing
Class IDs
Subnet Mask
Network ID
IP Addressing and Ethernet
TCP/IP Basics
Domain Name System
Internet Control Message Protocol (ICMP)
IPv6
IPv4
Time-domain reflectometer
Testing copper cable runs
Test cable runs
Installing a Physical Network
Backbone
Physical Connections
Wide Area Network
Copper-Based 10 GbE
Fiber-Based 10 GbE
Multiple Types of Gigabit Ethernet
Mechanical Connection Variations
SFF Fiber Connectors
1000BaseLX
1000BaseSX
1000BaseX
1000BaseT
100BaseFX
100BaseT
Modern Ethernet
Spanning Tree Protocol
Local Area Network
Network switch
Carrier-sense multiple access with collision detection
10BaseFL
Unshielded Twisted Pair
TIA/EIA Standards
RJ-45
10BaseT
Bus Ethernet
802.3 Standards
Ethernet Basics
Institute of Electrical and Electronics Engineers
Fire Ratings
Other Cables
Modal Distortion
Light Emitting Diode
Fiber-optic Cabling and Connectors
Ethernet
Twisted pair
Coaxial cable
Cabling & Connectors
Network Topologies
Connection-oriented vs Connectionless communication
Internet Layer
Transmission Control Protocol
Router
IP Address
Internet Protocol
Frame
NIC
Internet protocol suite
Networking
2020 10 12 13 31 39 Z Emi
2020 10 14 13 08 00 Z Hub
2020 10 16 14 11 20 Z Crossover Cable
2020 10 17 16 01 02 Z Baseband
2020 10 17 16 02 37 Z Broadband
2020 10 17 16 16 48 Z Half Duplex Ethernet
2020 10 17 16 18 12 Z Full Duplex Ethernet
2020 10 17 17 07 00 Z Sonet
2020 10 17 17 39 19 Z IEEE 802 3ba
2020 10 18 16 10 56 Z Work Area
2020 10 18 16 11 20 Z Demarc
2020 10 18 17 54 17 Z Equipment Racks
2020 10 18 18 01 09 Z Patch Panel
2020 10 18 18 08 09 Z ANSI TIA 606 C
2020 10 18 18 23 23 Z TIA EIA 568 Specification
2020 10 18 18 34 24 Z Customer Premises Equipment CPE
2020 10 19 12 53 32 Z Cable Run
2020 10 19 12 54 10 Z Cable Drop
2020 10 19 12 56 25 Z Telecommunications Room Location
2020 10 19 13 03 11 Z Pulling Cable
2020 10 19 13 06 29 Z Making Connections
2020 10 19 13 10 29 Z Crimping Rj 45
2020 10 19 13 18 27 Z Testing Fiber Cable Runs
2020 10 19 13 26 24 Z Crosstalk
2020 10 19 13 30 04 Z Attenuate
2020 10 19 13 57 29 Z Pci
2020 10 19 13 58 29 Z Pcie
2020 10 19 14 17 49 Z Ups
2020 10 19 14 20 51 Z Toners
2020 10 21 12 51 45 Z IP Header
2020 10 21 13 09 55 Z Tcp Header
2020 10 21 13 19 41 Z HTTP
2020 10 22 14 38 32 Z Unicast Frame
2020 10 22 14 42 07 Z ARP Command
2020 10 26 12 57 15 Z Interconnecting Lans
2020 10 26 13 03 07 Z Default Gateway
2020 10 28 14 41 04 Z Soho
2020 10 28 16 44 13 Z Spf
2020 10 28 17 01 08 Z Dkim
2020 10 28 17 03 36 Z Email
2020 11 03 14 50 56 Z Dynamic IP Addressing
2020 11 05 13 33 15 Z Mls
2020 11 05 14 30 31 Z Port Address Translation PAT
2020 11 05 14 38 09 Z Port Forwarding
2020 11 05 14 57 33 Z Dynamic Routing
2020 11 05 15 00 59 Z Routing Metrics
2020 11 06 15 00 42 Z Maximum Transmission Unit MTU
2020 11 07 15 38 21 Z Working With Routers
2020 11 07 16 05 40 Z Troubleshooting Routers
2020 11 09 14 39 30 Z TFTP
2020 11 10 14 12 04 Z Port Numbers
2020 11 10 14 25 53 Z Connection Status
2020 11 10 14 44 53 Z Ps
2020 11 10 14 46 48 Z Good vs Bad Connections
2020 11 10 14 52 00 Z HTML
2020 11 10 14 53 15 Z Xml
2020 11 10 15 00 13 Z Tls
2020 11 11 15 45 14 Z Telnet
2020 11 11 15 51 24 Z E Mail
2020 11 11 15 53 17 Z POP3
2020 11 11 15 53 43 Z Imap4
2020 11 11 15 58 38 Z E Mail Servers
2020 11 12 15 03 53 Z E Mail Clients
2020 11 12 15 06 25 Z FTP
2020 11 19 15 35 29 Z Dcv
2020 12 02 15 50 27 Z Troubleshooting DNS
20200628165447 Alias Test
20200628165447 Alias
20200628165833 Apropos
20200628170239 Aspell
20200628170530 Bg
20200628170734 Bzip2
20200628184557 Cd
20200628184725 Chgrp
20201008085520 IP
20210904130017 New Test Link 6
20220926182945 It Aphorisms
2023 04 13
2024 04 18
2024 04 23
2024 05 06
Readme
1000 Year House
20220217091103-network-segment
20220315174744-discretionary-access-control
20220315205700-plaintext
20220319092814-Review-PT3-n10-008
20220319095139-storage-area-network
20220319095304-software-defined-network
20220319100158-network-architectures
20220319104905-defense-in-depth
20220319105115-principle-of-least-privilege
20220319105401-rbac
20220319110956-separation-of-duties
20220319111229-honeypot
20220319111746-zero-trust
20220321163659-root-pw-rotation
20220331080858-expect
20220406080732-here-strings
20220419094714-public-key-cryptography
20220419114857-challenge-response-authentication
20220419115151-openssl
20220513122736-linux-firewall
Acceptable Use Policy
Access Control
Access-control list
Active Directory
Advanced Encryption Standard
Advanced Networking Devices
Aesthetics
ale
Algorithm
Alternative VPNs
Amazon Web Services (AWS)
Anonymous Fox Hack
Antivirus software
Apache Benchmark
Apache Reverse Proxy Setup
Apache Section
Apache Tomcat
API
append() and insert()
Application firewall
Application Layer
Application Layer (OSI Layer 7)
Application Service Provider
APS Pipeline "Roadmap"
APS Pipeline Review
apt
Architecture
Archiving And Backup
Arguments
ARIN
Arithmetic Evaluation
Arithmetic Expressions
Arithmetic Operators
arp
ARP cache poisoning
Array Indexing
Array Operations
Arrays
Assignment Operators
Associative Arrays
Asymmetric digital subscriber line
Asynchronous Transfer Mode
Augmented Assignment Operators
Authentication
Authentication Authorization and Accounting (AAA)
Authorization
Automation
Automotive
Autonomous system (Internet)
Awk
Awk Notes
Bandwidth (computing)
Bandwidth (signal processing)
Bandwidth management
Bash
Bash Expansion
Bash Script Header
Bash Scripting
Bash Scripting Style
Bash Variables
Basic Parameters
Basic Rate Interface
bc
Bed
Big Five personality traits
Bind mount
bind-mount
Bit numbering
Bit Operations
bit rate
bitwise operation
Block cipher
Boolean Operators
Boolean Values
Break Statements
Bridge Protocol Data Unit
broadcast domain
Brute force
Built In Functions
Business continuity planning
Career
Carrier wave
Case
Case Modification
cat
CCMP (cryptography)
Challenge-Handshake Authentication Protocol
Change management (engineering)
Change request
Chapter 1 Review Questions
Check If Key Value Exists In A Dict
chmod
Class Inheritance
Clause
Clean Energy
Climate Change
Climbing Out Of The Hole
Cloud-init
CloudLinux
Code Blocks
Code Linting
Code-division multiple access
Coffee Table
Command Substitution
Commands
Common Address Redundancy Protocol
Common Data Types
Common Functions
Communication protocol
Companies of interest
Comparison Operators
Comparison Operators
Complex PTSD
Compromised system
CompTIA Network+ Certification - All In One Exam Guide
computer
Computer hardware
Computer network
Computer Networking - a Top Down Approach
Computer science
Computer security
Concepts
Conditions
Congfiguring a VLAN-Capable Switch
Connection-oriented communication
Connectionless communication
Containerization
Content Switch
Content-addressable memory
Continue Statements
Continuity test
Continuous Deployment (CD)
Continuous Integration (CI)
Control Operators
Control system
Converting Types With list() and tuple()
Cool Dev Shit
Copper
Copper cable certification
Copper conductor
copy Module
Cpanel Section
CPSP
Create subdomain with cPanel uapi
Creating and Using a Class
Creating Arrays
Cryptography
cut
Data
Data communication
Data Link Layer (OSI Layer 2)
Data Loss Prevention
Database
Datagram
DDNS
Debugging
Decision Making
Deep packet inspection
Def Statement
Defense in Depth
Defensive Programming
del Statement
demodulation
Denial-of-service attack
Deploying My Blog
Deploying My Second Brain
Depression
Desk
Development
Development Strategies
DHCP
DHCP and VLANs
Dictionary Data Type
diff
Differentiated services
dig
dig
Digital data
Digital Signatures
Digital subscriber line
Dijkstra's algorithm
Dining Table
Direct-sequence spread spectrum
Directory Stack Builtins
Disable Strict Mode MySQL
Disaster recovery
Distribution frame
Diy Desk
DMARC
DMVPN
dnf
DNS Cache Poisoning
DNS Load Balancing
DNS Records
DNS Servers
DNS Zone
DNSSEC
Docker
Documentation
dot-decimal notation
dpkg
DRY
DTLS VPN
Dynamic Adaptive Streaming Over Http
Dynamic Multipoint Virtual Private Network
Editing Tricks
EIA
Electric current
Electrical network
Electrical resistance and conductance
Electromagnetic radiation
electronics
Elif Statements
Elk Stack
Else Statements
Enabling Nested Virtualization
Encapsulation (networking)
Encapsulation/De-Encapsulation
Encryption
Encryption and OSI
End of Life (EOL)
Endpoint security
enumerate()
Escape Characters
Ethernet frame
Ethernet over twisted pair
Exception Handling
Exit Status
Extended Test
f-strings
Fiber-optic communication
File Permissions
File Redirection
File Redirection And Looping
File Test Operators
Finance
find
Firewall (computing)
First Call Resolution
Fitness
fmt
fold
Food Log Program
For C Language Form
For Loops
For Loops
Forwarding Information Base
Foward Lookup Zone
FQDN
FTP Server Setup
Functions
Functions In Bash
Fundamentals Of The Openstack Cloud
Furniture
Generic Routing Encapsulation
Generic Tomcat Installation and Setup - cPanel version
get()
Git
Global Statements
GNU Stow
graphical user interface
Green Energy
grep
Grit
Grouping Commands
gzip
H.323
Hacks/Malware
Hash
Here Documents
hertz
Homelab
host
Host-based intrusion detection system
HTTPS
Hugo
IANA
ICANN
id
Ideas
Idempotence
Identity management
IEEE 802
If Statements
If Then Constructs
IM Wiki
imapsync
Immutable Data Type
Importing Classes
Importing Modules
in and not in Operators
in and not in String Operators
In Place Upgrade Ubuntu
Incident management (ITSM)
Indentation In Bash
Index
Indexing And Slicing Strings
info
Initial Thoughts On The Aps Pipeline
Initialization vector
InnoDB
Input Validation
Insider threat/malicious employee
Install Apache SVN
Install Composer
Install Elasticsearch
Install GCC for gRPC dependency
Install Joomla
install libsodium
Install Magento
Install Node.js
Install Php
Install PHP 7.4
Install PHP-FFMpeg
Install PrestaShop
Install Python 2.x
Install R
Install Varnish
Install WordPress
Integer Comparison Operators
Integrated Services Digital Network
Integrity
Interior gateway protocol
Intermediate distribution frame
Internal Field Separator
Internet
Internet access
Internet Group Management Protocol
Internet protocol suite
Internet Security Association And Key Management Protocol
Internet Service Provider
Internet Standard
InterVLAN Routing
Introduction to Vi
Intrusion detection system
Intrusion Detection/Intrusion Prevention
Investigating Load And Resource Usage Section
IP Helper Address
ipconfig
IPsec
iptables
islower()
isupper()
isX() Methods
items()
Jinja
JMeter
Job Control
Job Scheduling
Jobs
Jobs of interest
join()
k6
Kerberos
Kettlebells
Key (cryptography)
Key (cryptography)
keys()
Keyword Arguments
kill
KISS
Kubernetes
L2TP VPN
Latency
Learn Python
Learning
Learning Strategies
Leased line
Len
less
light
Lightspeed
Lightweight Directory Access Protocol
Link Layer Discovery Protocol
link-local address
Link-state advertisement
Link-state routing protocol
Link/Network Interface Layer
Linux
Linux Boot Process
Linux CLI
Linux Commands
Linux File System
Lisp
List
List Concatenation And Replication
List of TCP and UDP port numbers
Load Balancing
Load Testing
Load Testing and Capacity Planning for Databases
Local And Global Scope
Local User Authentication Files
logger
Logical and Comparison Operators
Logical Link Control
Logical Operators
lower()
Lua
MAC
MAC Address
Making Scripts Executable
Malware
Man-in-the-middle attack
Manage Empty Variables
Managed Hosting FAQ
Managed Hosting Training
Mandatory Access Control
Map the runs
Markdown
Markdown Tutorial
Markdownlint
Markup
Mask (computing)
Materials
Math Operators
Maximum transmission unit
Mean time between failures
Mean time to recovery
Mean time to repair
Mechanical splice
Media Gateway Control Protocol
Medium-dependent interface
Meet With Sean
Men's Work
Mental Health
Menus
Method
metropolitan area network
MH Notes
MH Time Tracking
MH WTRs
Migrate Drupal
Migrations And Upgrades
Modal disperson
Mode (electromagnetism)
Modem
Modified S And S
Modsecurity
Modulation
Most significant bit
mount
mount (unix)
Multi-mode optical fiber
multicast
multicast address
Multifactor Authentication
Multilayer Switches
Multiline Strings
Multiple Assignment Trick
Multiprotocol Label Switching
Music
Music Production
Mutable Data Type
MyISAM
MySQL
MySQL Basics
Mysql Section
MySQL/MariaDB
Name Resolution
Named Pipes
NAS
Near-field communication
Neovim
Net use
netrw
netstat
Network Access Control
Network Address Translation (NAT)
network bridge
Network Control Program
Network Control Protocol
Network delay
Network Interface Unit (NIU)
Network Layer (OSI Layer 3)
Network Models
Network Monitoring
Network News Transfer Protocol
Network Operations and Management
Network packet
Network Protection
Network Security
network service
Networking Device
Networking hardware
Networking Notes
Next-generation firewall
Nginx
Nginx Section
nl
Node (networking)
Non Volatile Random Access Memory
None Value
Nonrepudiation
Normal mode
Notes 2021-04-19
Notes From Andyv
NTP/SNTP
Nutrition
Object Oriented Programming
Office
On Learning and Education
one's complement
One-way function
Online Certificate Status Protocol
Open Shortest Path First
Opening Files
OpenSSH
Openstack
Optical fiber
Optical fiber connector
Optical time-domain reflectometer
OSI Model
OSSEC
Package Management
Packer
Packet analyzer
packet switching
Packet/Protocol abuse
pacman
Pandoc
Parameter Expansion
Parameters
partition()
Passing References
pathlib Module
Payload (computing)
PEP 8 -- Style Guide for Python Code
Performance & Optimization
Performance Tuning
peripheral
Personal Development
Phase Change Memory
Php Section
PHP-FPM
Physical Layer (OSI Layer 1)
Physical/Local Access
PID controller
ping
Pipeline
PKI
Plain Text Accounting
Playbooks
Plugin Philosophy
Point-to-Point Protocol (PPP)
Point-to-point telecommunications
Pop
Port Bonding
Port Number
Positional Parameters
PowerShell
PPTP VPN
Practice Test 2 N10-008
Presentation layer (OSI Layer 6)
Primary Rate Intrface
printf
Private Cloud Training Meeting
Private network
Problem Solving
Process Substitution
Productivity
ProFTPD Installation
Program Execution
Programmable logic controller
Programming
Programming Paradigms
Prometheus
Proposed "Roadmap"
Proposed Work-flow for Authoring Wiki Articles using Markdown and Pandoc
Protecting Your Network
Protocol data unit
Proxmox VE
Proxy Pass
ps
Psychology
Public key certificate
Public switched telephone network
Public-key cryptography
Putting Scripts In Your Path
Pyinputplus Module
pyperclip Module
Python
Python Notes
Qa Guidelines For Managed Hosting
QoS and Traffic Shaping
Quality of service
Radio wave
RADIUS
Random Access Memory
random Module
Range Function
Raw Strings
read
Read Builtin
Reading Files
Real Time Streaming Protocol
Real-time Transport Protocol
Recursive Acronym
Reference
Regular Expressions
Regular Expressions in Python
Remote access service
Remote desktop software
remove()
Replay attack
Repository
Resume
Return Statement
Reverse Address Resolution Protocol
Reverse Lookup Zone
reverse()
Review Ptn008
RHCSA Notes
Risk management
RoundCube Database Connection Error
Routing Information Protocol
RSA (cryptosystem)
rsync
sar
Saving Variables
Saving Variables With pprint.pformat() Function
SCADA
Scoping In Bash
SCP
Scripting
Securing TCP/IP
Security
Security Association
Security policy
sed
sed
Server Optimization
Servers
Service-level agreement
Session hijacking
Session Layer (OSI Layer 5)
setdefault()
SFTP
Shell Prompt
Shell Startup
shutile Module
Signal
Simple And Sinister
Simple Gateway Control Protocol
Simple Network Management Protocol
Single-mode optical fiber
Slice
Small form-factor pluggable transceiver
SMTP
Social Engineering
Socket Pairs
Sofa
SOLID
sort
sort()
Source Control Management (SCM)
Spaced Repetition Memory
Special IP Addresses
Special Parameters
Specialized Networks
Split pair
split()
Spoofing attack
Squat
Squat Mobility
SSH client
ssh-copy-id
ssh-keygen
SSL VPN
SSL/TLS
SSL/TLS
Standard Library
strace
String Comparison Operators
String Concatenation And Replication
String Interpolation
String Literals
String Operations
Strings In Bash
Styling Classes
Subnet
Subnetwork
Substitution
Sustainability
swapcase()
Switch Management
symlinks
symmetric digital subscriber line
Symmetric-Key Encryption
sys.exit()
Sysadmin
Syslog
System resource
systemd
systemd-journald
Systems theory
T1 Pipeline Audit
T1 Pipeline Roadmap
T1E Pipeline "Roadmap"
T1E Pipeline Audit
TACACS+
Tagging
tar
TCP Segment
TCP/IP Applications
tcpdump
Telecommunication
telecommunications network
telephone line
Temporal Key Integrity Protocol
Temporary Files
Terraform
Test Builtin
Testing
Text And Number Equivalence
Text Editors
The Call Stack
The CIA Triad
The Depression Cure - One Pager
The Practice Of System And Network Administration
Therapy
Thoughts On Videos
Throughput
TIA
Tickets
Tilde Expansion
Tire Sizes
Tmux
To Review
To Review from Practice Test 1
To Review PT1 2021-07-24
Top Down Design
TPMS
tr
traceroute
Transmission (telecommunications)
transmission medium
Transport Layer (OSI Layer 4)
Transverse mode
Trap Builtin
tree
Troubleshoot Guides
Troubleshooting Strategies
Troubleshooting TCP/IP Networks
Trunking
tty
Tunneling protocol
Tuple
Turnaround time
umask
umount
Unary Operators
uniq
Unix
Until
Updating Vim Plugins
upper()
Upstream (networking)
Uptime
User Datagram Protocol
User Management
Users and groups
Vagrant
Vale
values()
Variable Name Expansion
Variables
Variables In Bash
Vim
Vim Cheat Sheet
Vim spell
Vimrc
Vimscript
Virtual Routing And Forwarding
VirtualBox
VLAN
VLAN hopping
VLAN Trunking Protocol
Voice frequency
VOIP
VPN
Vulnerability assessment (computing)
Wait Builtin
Waveguide
Webmin Installation
Webservers
Websockets
While
While Loop Statements
Wi-Fi (WiFi)
Wi-Fi Protected Setup
Wiki
Windows
Wired Equivalent Privacy
Wireless network
Wireless Networking
Wireless Networking Standards
Work Training
Work-Flow Optimization
Writing Files
X.509
xargs
XOR
YAGNI
YAML
Zero-day attack
Zeroconf
Zettel Id
Zettelkasten
zypper

Troubleshoot Guides

RoundCube Database Connection Error