Finding the right piece of information that you need from a Cisco router can often be a challenge. For example, if you use the show running-config command on a large production router, you can end up with 25 pages of text output. Locating that one piece of information you’re looking for can take a lot […]
Finding Configuration Details Quickly in Cisco IOS Read More »
Similar to a Windows or Linux operating systems that have a command line or terminal commands to manipulate files, the Cisco IOS (though rooted in Unix) and has its own list of commands to manipulate files. These commands are very similar to DOS/Windows commands. Files could be your IOS router operating system executable, configuration file(s),
File Commands and their Usage in Cisco IOS Read More »
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 good that you’ll
Cisco IOS Order of Operations for NAT and QoS Read More »
For those of you who love Wireshark and are supporting Wi-Fi Wireless networks, we would like to offer a great default profile for WiFi. Let’s make no bones about this capturing and analyzing Wi-Fi traffic is not as easy (you have to be in Monitor Mode) as just selecting this profile and clicking capture.
A Wireshark Wi-Fi WLAN Troubleshooting Configuration Profile Read More »
What is EtherChannel? EtherChannel technology is another way for you to increase the bandwidth of your core network links and provide redundancy of LAN links. It allows you to achieve greater speed by bundling Fast Ethernet or Gigabit Ethernet links, which makes a switch or router use the merged ports as a single port. This
Configuring EtherChannel on Cisco Switches Read More »
No one wants it to happen but, sooner or later, you will experience a router crash. When you do, you will want to be prepared to save that critical router memory information in order to find out why the router crashed and prevent future crashes. To do this, you need to configure your router to
Core Dump in Cisco IOS Read More »
Most users of Wireshark and T-Shark are completely unaware that neither of these programs alone actually captures packets! So wireshark people (and others), let’s dig in. Check out these great references as well: Our custom profiles repository for Wireshark Our Udemy course on Wireshark Our Udemy course on Wireless Packet capture Both programs use a
How To Use ‘dumpcap’ Natively on your Computer Read More »
For those of you who love Wireshark and are needing to analyze ARP packets, we have the profile for you. Profiles are one of the most important Wireshark capabilities. Setting up and using different profiles for different environments, protocols, and tasks is a crucial skill that we teach in our Wireshark courses. Let’s say you
A Wireshark ARP Configuration Profile Read More »
For those of you who love Wireshark and are needing to analyze DNS Queries and Responses, we have the profile for you. Profiles are one of the most important Wireshark capabilities. Setting up and using different profiles for different environments, protocols, and tasks is a crucial skill that we teach in our Wireshark courses. Let’s
A Wireshark DNS Configuration Profile Read More »
For those of you who love Wireshark and are supporting IPv4, we would like to offer a great default profile for IPv4. Profiles are one of the most important Wireshark capabilities. Setting up and using different profiles for different environments, protocols, and tasks is a crucial skill that we teach in our Wireshark courses. Let’s
A Wireshark IPv4 Configuration Profile Read More »
Most network engineers and technicians are quickly discovering that with “everything over IP” we are required to understand exactly what this means. For a lot of the standard, traditional data communications between clients and servers this means transport over TCP. Furthermore, it requires the ability to troubleshoot TCP. To troubleshoot TCP you have
A Wireshark TCP Troubleshooting Configuration Profile Read More »
For those of you who love Wireshark and are supporting BGP, we would like to offer a great default profile for basic BGP. Consider for a moment what would be important in your network administration in basic BGP: Being able to filter BGP packets quickly, as well as finding potentially bogus BGP Colorizing BGP message
A Wireshark Basic BGP Configuration Profile Read More »
Check out these additional IPv6 Resources: Our IPv6 overview course at Udemy Our IPv6 Custom Profiles for Wireshark Our IPv6 classes at the Online School For those of you who love Wireshark and are supporting IPv6, we would like to offer a great default profile for IPv6. Consider for a moment what would be important
A Wireshark IPv6 Configuration Profile Read More »
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 for this message
CONFIG_RESOLVE_FAILURE error Quick Fix in Cisco IOS Read More »
Sometimes, we need to transfer IOS from one router/platform to another. Other times, we can end up in Rommon> prompt because an IOS download failed of similar issue. Let’s start with a stranded router. It is strongly suggested that you get a PCMCIA memory card, insert it into a good router. From priviledged mode on
Copying Cisco IOS from One Router to Another Read More »
