Main Page
Whereas some pages here are relatively new, most have not been updated in a long time. __NOEDITSECTION__
Linux
- Getting started with Linux
- Nagios
- Debian / Ubuntu Vs RHEL / CentOS / Fedora
- Open file handling List open files by process and set system and process limits
- Less Tricks
- SVN for /etc Version control your /etc
- Vi/Vim
- Convert Windows/DOS text file to Unix/Linux and vica verca
- Force password change at next login
- Chmod codes
- Installing Perl Modules
- Setup Squid Forward Proxy with Basic authentication
- Convert date format
- Disk Partition alignment
- VNC Quickstart (Ubuntu)
- File timestamps
- Calculate Sum and Average using Awk
- Get Motherboard / Manufacturer information from the command line
- Get Hard disk manufacturer and model
- Ascertain what package provides a given binary with rpm
- Extract IP address from string using grep
- Copy file to multiple locations
- Block / Ban MAC address in dhcpd
- Create file with exact / specific size
- X Windows & Desktop Tricks
- Awk Tricks
- Syslog
- Logrotate
- Max file descriptor limit
- Scan for SSH servers using nmap
- ARP Cache Timeout
- Disable Caps lock in Ubuntu 16.04
- Setup Gitlab behind off-loaded/reverse proxy SSL (such as AWS ALB)
Troubleshooting
- Linux System Troubleshooting
- Couldn't open /dev/null Error
- [[Can't open /dev/tty: No such device or address Error (Linux)|Can't open /dev/tty: No such device or address
Error]]
- Ping: icmp open socket: Operation not permitted
- Possible SYN flooding on port xxx. Sending cookies
- Error: Could not find/open font when opening font "xyz", using internal non-scalable font (gnuplot)
- Error: mount: wrong fs type, bad option, bad superblock (NFS)
SSH
- SSH Tunnels
- Append a remote file using SSH
- Verify SSH server host key
- Public key authentication for SSH
- Force Password Authentication on SSH
Networking
- Virtual IPs/Multiple IPs on one Network Interface (Debian/Ubuntu)
- Increase simultaneous/concurrent TCP connections
- Capture DHCP packets using Tcpdump
- Count Network connections by state
iptables
- Getting started with iptables
- Send all incoming traffic on an interface to a listening port
- NATing
- Prevent brute-force attack by rate-limiting connections (iptables)
Troubleshooting
Scripting
- Regular Expressions
- Python script fails with ": command not found"
- Getting started with Java Jars and Classes
Bash
- Bash Scripting
- Bash Tricks
- Set Bash Loop Delimiter
- Sourcing variables from other files using Source command
- Writing defensive Bash scripts
- Command substitution
- Set default value script/function parameter
- Remove spaces or any character from a string
Perl
- Loops
- Parameters
- Subs
- Numeric and String variable operations
- Extracting text
- Numeric and String comparison
- Associative Arrays
- Calling subs from separate script
Microsoft Windows
- Registry
- Change Product Key (Windows XP)
- Startup Methods
- Console session (Terminal Services/Remote Desktop)
- DOS Scripting
- Accessing a server remotely when RDP/Terminal services is down
- Performing functions via the command line
- Rename Mapped or Network Drives Automatically
- Visual Basic Scripts
- Create custom System Folder on the Desktop or My Computer
- Delete files based on age
- WINS Lookup tool
- Disable Group Policy for individual PC locally
- Set Terminal Service session Timeouts/Limits
- Windows DOS Tricks
- FSMO Roles
- FSMO Role Placement
- Disk Partition alignment
- Windows Installer Cleanup Utility - use this to remove persistent install dialogs etc.
Troubleshooting
- Context Menu Handler (Explorer)
- Restore/Repair My Documents
- Icon problem: Low colour icons (4 bits/16 colours) even with 16/32 bit screen mode
- Cannot View Source (Internet Explorer)
- System writer is not found in the backup Error (Windows Server Backup)
- Domain Controller is not advertising as a time server Error in dcdiag
Visual Basic Scripts
Main page: Visual Basic Scripts
- Add Whitelist functionality to Intelligent Message Filter/IMF (Exchange)
- Email notifications for NTBACKUP
- Delete all files older than 1 day
Web
- Linux Web Troubleshooting
- SSL Certificates with Globalsign on Firefox
- Rewrite on IIS that actually works
- Apache Rewrite
- Apache Digest Authentication
- Telnet port 80 whilst specifying Hostname
- OpenSSL
- SSL Cert Format converter
- Renew or Create New Certificate Signing Request (CSR) While Another Certificate Is Currently Installed on IIS
- Forward DNS traffic over SOCKS proxy (Firefox)
- Simple Apache log file analyser using Awk
Version Control
CVS
SVN
- Getting started with SVN
- Can't open file '/mnt/svn/dns/db/txn-current-lock': Permission denied Error
GIT
Networking
Cisco
- Cisco Tricks
- Change MTU for interface and check for too-large packets
- NTP
- Check DSL Line Noise
- Restrict management (telnet) access based on IP
- Syslog
DNS
- SOA record
- Ascertain and Hide the BIND Version Number
- Find duplicate PTRs in a zone file
- Bad owner name (check-names) Error
- DNS Failover / High Availability
Microsoft Exchange 2000/2003
- Allow Out of Office replies to external addresses
- Non-Delivery Report (NDR) / Bounce Codes
- Add Whitelist functionality to Intelligent Message Filter/IMF
- Restore Exchange using NTBACKUP
- Re-create Outlook Web Access (OWA) Virtual Directories
- Stop Producing Backscatter Spam
Troubleshooting
- Exmerge Error CADRoutines::GetNamingContextData
- Exmerge error 0x8004011d
- Error -514 JET errBadLogVersion when using Eseutil
- POP3 Connection hangs and other issues
- One or more users currently use a mailbox store on this server Error
- Strip Apostrophe (or any character) in SMTP email address
Microsoft Exchange 2007 / 2010
- Exchange 2007 Server Roles
- Monitoring Exchange 2007 using Nagios
- Exchange 2007 CAS/Hub Transport Notes
- Standby Continuous Replication
- Non-Delivery Report (NDR) / Bounce Codes
- Restore Exchange using NTBACKUP
- Settings permission for an Exchange database / Granting access to all mailboxes
- Stop Producing Backscatter Spam
- Get Last Logon Time, Last Logoff time, Mailbox size and Item Count
- Setup Registered Block List (RBL) checking
- Automate/Schedule Exchange cmdlet
- Searching the Anti-spam Agent Log
- Get Database Last Backup time
- Setup Email size limits
Troubleshooting
- Exmerge Error CADRoutines::GetNamingContextData
- Exmerge error 0x8004011d
- Error -514 JET errBadLogVersion when using Eseutil
- Bounce 550 5.7.1 RESOLVER.RST.AuthRequired; authentication required
- Exchange 2007 property cannot be set due to version 0.1 (8.0.535.0) or later required
- Strip Apostrophe (or any character) in SMTP email address
- Error -18597 in Entourage when connecting to Exchange 2007
Databases
Microsoft SQL Server - MSSQL
- Monitor SQL Server using Nagios
- Setting up Mirroring
- SQL Log shipping
- SQL Clustering
- Obtain Service pack details
- High availability IIS & SQL using NLB & Clustering
- Backup all DBs on a SQL Server
- Create Database T-SQL script
MySQL
- MySQL Troubleshooting
- Access rights/Privileges/Grants
- Reset Root password
- Set Global Variables
- Get or Ascertain Slave Lag
- Access denied for root when granting privileges in MySQL
PostgreSQL
- Getting started with PostgreSQL
- MySQL vs PostgreSQL
- List tables in all schemas
- Get Database, Schema and Table Sizes
- View locking transactions
- Always use the pager
- Set Default Schema / search_path
- Find and replace - regexp_replace
- Output Query as CSV
- Copy table structure only
- Group by day, week or month
- Checkpoint
- Background Writer (bgwriter)
- Show trigger SQL
Microsoft Outlook
- Disable Attachment Blocking
- Always add BCC line
- View another user's calendar in Outlook Web Access (Exchange 2007 OWA)
Troubleshooting
- ActiveSync Error 0x85010005 (Outlook Mobile Access)
- ActiveSync Error 0x80072F0D (Outlook Mobile Access)
- Global Address List not updating
- Bounce when Sending Meeting Request
- Security certificate is invalid or does not match the name of the site Error (Outlook 2007)
- Your Out of Office settings cannot be displayed Error (Outlook 2007)
CA Brightstor Arcserve Troubleshooting
- Database Corruption
- Database login problems / Cannot run VLDB utilities / -2005 error
- Reinitialise database
Lotus Notes Troubleshooting
- Your availability time range is invalid, please correct Error
- Document has already been deleted Error
- Stationary Locked for other users
Disaster Recovery / Backup
Reference
- Global Address List (Exchange)
- System Volume Information folder
- Difference between Quick Format and a normal/long Format
- RAID Types
- Swap / Virtual memory