As we said in our basic ACL How To, ACL’s’ are vital to networking today. Everyone uses them, and proper usage is imperative. In this How To, we are going a little deeper into two ACL types: Intrastructure and Transit. We will discuss the two with examples and you will clearly understand the difference between […]
Access Control to Infrastructure (iACL) and Transit (tACL) Read More »
What is NBAR? NBAR is a powerful packet filtering/identification/firewall that you may already have installed on your Cisco router. For a list of what NBAR can detect look here. NBAR is also what we call Cisco’s “autopilot” for QoS. It has been in IOS since ver. 12.0 and has been continually updated with recognition of
NBAR Explained in Cisco IOS Read More »
The order of operations is hard coded into Cisco IOS and tells the router how to process traffic according to the configuration of different router functions and features. While we cant’ make you think like a router, it is likely you have already picked up on some of these. When configuring features such as Network
Order of Operations in Cisco IOS Read More »
When a router has to forward a packet, it looks in its routing table to match as many bits as possible of the destination address to a route in its routing table. This is known as longest match routing. Once a match is found, the router forward the packet to the next hop defined by
Administrative Distances in Cisco IOS Read More »
What happens if there is a system or user on a VLAN that is infected by malware or is deliberately running a scanning program? This can cause a massive amount of entries in the CAM Table of the switch. Think of the CAM table as the MAC address table. There is a certain limit of
CAM Table Overflow Attack Mitigation on Cisco Switches Read More »
This How To explains the fundamentals of configuring EIGRP. EIGRP is an advanced distance-vector routing protocol that is used on a computer network to help automate routing decisions and configuration. The protocol was designed by Cisco Systems as a proprietary protocol, available only on Cisco routers, but Cisco converted it to an open standard in
EIGRP Configuration in Cisco IOS Read More »
This How To explains how to fix an annoying default behavior on Cisco IOS. Mistype a command on a Cisco router and the router thinks you just typed a hostname. This is often an annoying problem. For example: Router#shwoTranslating “shwo”…domain server (10.1.1.1) % Unknown command or computer name, or unable to find computer addressRouter# Here,
Stopping the Cisco Router from Trying to TELNET Read More »
It is a great day! Mr. Walding’s book on MPLS is now available on the iTunes/iBooks! This book on MPLS (MultiProtocol Label Switching) reveals what MPLS is, how it works, what services it provides, and what problem it solves in networking. Instead of reading dozens of standards documents, this book summarizes and illustrates the
Mr. Walding’s Book on MPLS Released Read More »
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 As more and more of you are moving to Voice over IP, you will want to use Wireshark to do voice analysis. But first, you may want to run a
Using tshark for Packet Voice Read More »
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 As many of you know, T-Shark is the command line version of Wireshark. For T-Shark beginners, look first here.For more advanced T-Shark users, read on.I often get asked for T-Shark
tshark Usage Examples Read More »
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 Using Wireshark Coloring Rules – Some Notes A great site with additional coloring rules offered to the community: http://wiki.wireshark.org/ColoringRules All default coloring rules are stored in a file Computer> Local
Using Coloring Rules in Wireshark Read More »
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 If the Wireshark host performs TCP and UDP checksum offloading – the process of calculating the checksum on the NIC and not by the protocol stack – Wireshark will trip
Removing Checksum Calculations in Wireshark Read More »
In 2012 and 2013, all the buzz in networking was about the emergence of Software Defined Networking (SDN). Frankly, that buzz continues in 2014 and vendors continue to refine and define their role in this market segment. Like a game of chess, the players are all stating their objectives, their product plans, and their new
What will be the Software Defined Networking (SDN) Skills Needed? Read More »
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 We all know what a great tool Wireshark is. One of the features added to Wireshark is the ability to temporarily colorize an Ethernet, IP, TCP or UDP
Using Wireshark Temporary Colors to easily see a Conversation Read More »
Comcast revealed last year that it intended to deliver a special high speed option for Internet service at up to 105Mb/s. An article in USA Today reports: “Extreme 105, [will be] available to consumers in more than 40 million homes in San Francisco, Seattle, Denver, Chicago, Boston, Philadelphia, Washington, D.C., and Miami, among others. The
Downloading an HD Movie in 8 Minutes Read More »
