Troubleshooting TechNotes
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- "%Error opening tftp://255.255.255.255/network config" Error Message Prevention 03/Aug/2006
- Back up and Restore Configuration Files
- Buffer Tuning for all Cisco Routers 17/Jun/2016
- Capturing Text Output from Hyperterminal 25/Jun/2008
- How to Protect Your Network Against the Nimda Virus 06/Mar/2008
- Maximum Number of Interfaces and Subinterfaces for Cisco IOS Routers: IDB Limits 24/May/2012
- Performance Tuning Basics 11/Jul/2007
- Prevent "Translating. domain server (255.255.255.255)" Messages after an Invalid Command is Entered on a Router
- Problems Caused by Simultaneous Access to Router NVRAM 03/Aug/2006
- Reset Router to Factory Defaults 13/Sep/2023
- TCP and UDP Small Servers 01/Aug/2006
- Understanding the Definition of bits per second (bits/sec) from the show interfaces Command Output 01/Aug/2006
- Understanding the Ping and Traceroute Commands
- Use NBAR and ACLs to Block the "Code Red" Worm 02/Aug/2006
- How to Choose a Cisco IOS Software Release
- How To Copy a System Image from One Device to Another
- ROMmon Recovery for the Cisco 800 Series Router 18/Dec/2007
- Standard Break Key Sequence Combinations During Password Recovery
- Why Does My Router Lose Its Configuration During Reboot? 25/Jun/2008
- TFTP Server Selection and Use
- CAB-X21 MT and CAB-X21 FC Serial Cable Specifications
- CAB-530 MT Serial Cable Specifications
- CAB-449 MT and CAB-449 FC EIA/TIA-449 Serial Cable Specifications
- CAB-232 MT and CAB-232 FC EIA/TIA-232 Serial Cable Specifications
- CAB-25AS-FDTE Adapter Technical Specifications 30/Jan/2006
- CAB-25AS-MMOD Adapter Technical Specifications 27/Jan/2006
- Cabling Guide for Console and AUX Ports
- Cisco Cable Product Numbers, Part Numbers, and Descriptions 01/Aug/2006
- Ethernet AUI Port, Pinouts, and Cable Specifications
- Ethernet 100BaseTX and 10BaseT Cables: Guidelines and Specifications
- How to Connect a KG-84A to a Cisco Serial Interface 01/Aug/2006
- Serial Cable Connection Guide 01/Aug/2006
- 5-in-1 EIA/TIA-449 Assembly and Pinouts 01/Aug/2006
- 5-in-1 EIA/TIA-232 Assembly and Pinouts 04/Mar/2008
- 5-in-1 V.35 Assembly and Pinouts
- 5-in-1 X.21 Assembly and Pinouts 04/Mar/2008
- Dealing with mallocfail and High CPU Utilization Resulting From the "Code Red" Worm 20/Jun/2008
- High CPU Utilization in Exec and Virtual Exec Processes 12/Dec/2008
- The show processes Command
- Troubleshooting High CPU Utilization Due to Interrupts 29/May/2008
- Troubleshooting High CPU Utilization due to Processes 29/Sep/2008
- Troubleshooting High CPU Utilization on Cisco Routers
- What Causes %SYS-3-CPUHOG Messages? 24/Jun/2008
- Hardware Troubleshooting Index Page 06/Apr/2022
- Processor Memory Parity Errors (PMPEs) 25/May/2016
- SegV Exceptions 31/May/2016
- Troubleshooting Buffer Leaks 26/May/2016
- Troubleshooting Ethernet Collisions 01/Aug/2006
- Troubleshooting Router Interfaces and Modules Issues 07/Dec/2006
- Troubleshooting Watchdog Timeouts 21/Jun/2016
- Creating Core Dumps 24/Jun/2008
- Less Common Types of System Crashes 12/May/2016
- Troubleshooting Bus Error Crashes 16/Jun/2016
- Troubleshooting Router Hangs 02/Aug/2006
- Troubleshooting Spurious Accesses, Alignment Errors, and Spurious Interrupts 31/May/2016
- Understand Software-forced Crashes 16/Jun/2016
- What Causes a Router To Be Restarted By the Abort or Trace Trap Commands 29/Nov/2006
- ADSL POTS Primary Protection
- Bourns Primary Protection
- DSL Modem/Router Interface Pinouts and Status LED Descriptions 26/Feb/2008
- Most Common L2L and Remote Access IPsec VPN Troubleshooting Solutions
- Understanding and Configuring VLAN Routing and Bridging on a Router Using the IRB Feature 31/Aug/2009
Basic Concepts and Maintenance
Boot Failure Recovery and IOS Upgrade
Cables and Specifications
High CPU Utilization
Troubleshooting Hardware
Troubleshooting Router Hang and Router Crash
Miscellaneous
Support Documentation
Troubleshooting