CLI

Maintenance with the ‘show diag’ command in Cisco IOS

Post Views: 1,904 Routine maintenance is the underpinning of any well run network. Through routine maintenance, consistency, predictability and standardization all result allowing the network to operate as expected and in times of fault, makes a better troubleshooting environment. As part of any routine maintenance activity, Cisco provides several commands to help. One less known […]

Maintenance with the ‘show diag’ command in Cisco IOS Read More »

Leveraging Logging for Troubleshooting Using Cisco IOS

Post Views: 4,400 Whenever we teach our Hands-On courses, we always have a section of the course that discusses troubleshooting the network or technology the class is learning. A key part of troubleshooting any network is knowing the technology, no argument. But even the masters of technologies like Multicasting, or IP Networking, or MPLS, still

Leveraging Logging for Troubleshooting Using Cisco IOS Read More »

Service Timestamps in Logging in Cisco IOS

Post Views: 4,274 You can use the service timestamps command to create timestamps on the router’s log files. Since version 11.3, the Cisco IOS has enabled certain timestamps by default, so most of us have this on. However, there are additional timestamps options that you can enable as well as places where timestamps are probably

Service Timestamps in Logging in Cisco IOS Read More »

Keeping VPN SA’s Refreshed in Cisco IOS

Post Views: 1,154 Many people are using VPN technology today to ensure data confidentiality between remote locations. When using a site-to-site type VPN (say between a Router and a Firewall), a common complaint among end users is intermittent delay before VPN traffic is successful. This is usually due to Security Associations (SA) becoming too old

Keeping VPN SA’s Refreshed in Cisco IOS Read More »

Spanning Tree Protocol Configuration Basics in Cisco IOS

Post Views: 1,487 As many of our students and clients have learned, Spanning Tree in Layer 2 Ethernets is a basic control protocol that removes logical loops from physically looped networks creating the Spanning Tree. This How To focuses on the essential configuration commands in Cisco IOS that you need to know to manage Spanning

Spanning Tree Protocol Configuration Basics in Cisco IOS Read More »

IP Spoofing Security Tip in Cisco IOS

Post Views: 2,171 All router administrators need to take whatever security precautions they can to prevent attacks to their systems and networks. While these attacks are a continually moving target, a common attack to IP networks is called IP Spoofing. This is accomplished by sending IP packets into the network with source addresses that appear

IP Spoofing Security Tip in Cisco IOS Read More »

Cisco IOS Order of Operations for NAT and QoS

Post Views: 2,617 When learning Cisco IOS, students often ask, what happens if there is conflicting information? Cisco IOS order of operations plays an important role in how a router processes traffic and makes choices, especially if there are two possible answers. If you’re simply using the most basic features of the router, chances are

Cisco IOS Order of Operations for NAT and QoS Read More »

CONFIG_RESOLVE_FAILURE error Quick Fix in Cisco IOS

Post Views: 3,284 In this article, I will explain steps to correct a CONFIG_RESOLVE_FAILURE error in Cisco IOS. \If you are like many users of the latest IOS, you may find your routers constantly outputting a message like this: cell_pe1# %Error opening tftp://255.255.255.255/cisconet.cfg (Timed out) 19:20:43: %SYS-4-CONFIG_RESOLVE_FAILURE: System config parse from (tftp://255.255.255.255/cisconet.cfg) failed The reason

CONFIG_RESOLVE_FAILURE error Quick Fix in Cisco IOS Read More »

Scroll to Top