Post Views: 6,347 What exactly is the purpose of the IP ID field? This is actually a great question. While many have tried to answer the question in various articles on the Internet, I thought the question deserved a clear answer to the question. RFC 6864 updated RFC’s 791, 1122, and 2003 to clarify the
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Post Views: 2,105 This question (really two questions) has been popping up quite a bit lately. Let me see if I can explain. First, let’s define what SD-WAN is. SD-WAN leverages the SDN concept of separating the control plane from the data plane and creating a controller running software that can enact control and policies
What is SD-WAN? Does it replace MPLS? Read More »
Post Views: 1,794 That’s right! ARIN formally announced today that IPv4 Adresses are gone – gone – gone in North America: That means that everyone is down to whatever they have. It also means that if your organization is not prepped to convert to IPv6 with a solid plan, it ought to be! Plus you
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Post Views: 2,881 OSPF (Open Shortest Path First) is an IGP (internal gateway protocol), and OSPF is an open standard protocol originally defined in RFC 2328. Since then OSPF has been updated numerous times including functionality to support IPv6 and Address Families. OSPF is supported on every major routing platform as well as Windows Server
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Post Views: 2,271 IP mobility is software and hardware designed to provide network access as a user travels from network to network. Cisco calls this the ubiquitous connection. Cellular telephone networks already accomplish this: You can begin a cellular call in Los Angeles, CA and (in theory) you should be able to drive to New
IP Mobility Primer in Cisco IOS Read More »
Post Views: 6,983 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
A Wireshark DNS Configuration Profile Read More »
Post Views: 1,992 A common question folks ask is “How do you check the bandwidth utilization on a router?” It is a great question and the answer is not as easy as you would expect. There are tools that accomplish this (i.e. NetFlow and there is another mentioned at the end of this page). However,
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Post Views: 1,765 The Border Gateway Protocol (BGP) allows internal and external networks or autonomous systems (AS’s) to exchange routes. BGP is a path-vector routing protocol, which simply means that its job is to exchange routing information between autonomous systems to find the most efficient path for your data to the Internet. Each BGP router
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Post Views: 12,509 In my prior article on getting started with nmap, I showed you how to get started with this superb network scanner. In that article we did basic scans to locate what hosts were on a given network and display what services were running on those hosts. In this article I am going
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Post Views: 12,367 In the prior articles (Getting Started with nmap and Deeper Scanning with nmap), we showed you how to get started, and how to dive deeper with this superb network scanner. Let’s go even deeper! One of the cool things nmap has is the ability to create scripts. Now doing this from
Even Deeper Scanning with nmap Read More »
Post Views: 14,015 Nmap (“Network Mapper”) is a free and open source (license) utility for network discovery and security auditing that has been around since 1997. Surveillance and network scanning is often one of the first steps in Penetration Testing or Security Validation. Many systems and network administrators also find it useful for tasks such
Getting Started with nmap Read More »
Post Views: 12,744 Welcome to my little nmap cheat sheet! To learn more about nmap – check out my articles: Getting Started with nmap and Deeper Scanning with nmap and Even Deeper Scanning with nmap and Advanced nmap Scripting Engine. There was no intent here to recreate the full nmap capabilities, that would have been a waste
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