Open Shortest Path First (OSPF) • OSPF, or Open Shortest Path First, is a link-state, open-standard, dynamic routing protocol. OSPF uses an algorithm known as SPF, or Dijkstra’s Shortest Path First, to compute internally the best path to any given route. • OSPF is classless and converges fairly quickly, using cost as it’s metric. A …
300-100 CCNA Cisco exam prep
January 14, 2019
Cisco Network Essentials // HDLC
Cisco High-Level Data-Link Control (HDLC) protocol was once very popular ‘back in the day’. On a quick side note – I always try to explain things in a simply way with an easy to readability. With that comes the need to have an assumed knowledge in other specifics – in this article it would be …
business design Security technologies WiFi
October 31, 2018
Why Does Hotel WiFi Suck?
Free WiFi has become a necessity in the hotel industry. I’m loathed to write this next bit but I wouldn’t book a hotel without WiFi. guest expectations Most hotels, even the big boys, are reluctant to spend good money to do it right. Going back to the loathing part, guest surveys have repeatedly found that ...
300-100 Cisco exam prep
October 25, 2018
Cisco Network Essentials // EIGRP Part 1
EIGRP Characteristics Fast Convergence EIGRP uses the DUAL algorithm to converge very quickly. It does this by knowing neighbor router’s routing tables and predefining primary and secondary routes to every destination network. Multicast EIGRP sends route updates, hellos, and queries to its neighbours using the multicast address 224.0.0.10 so end hosts are not affected. Hellos …
300-100 Cisco exam prep
October 24, 2018
Cisco Network Fundamentals // Administrative Distance
Administrative Distance Routers need a way of determining which path to use to a destination network if two or more routing protocols are in use and both advertise a route. Administrative distance is Cisco’s answer. Cisco has assigned an administrative distance (AD) to each routing protocol that outlines which protocol a router will prefer. The …
300-100 Cisco exam prep
October 23, 2018
Cisco Network Fundamentals // Classful Concepts
Classful Concepts IP routing protocols are either classful or classless and that determines how they present route information. Classful Classful routing protocols (like RIPv1) do not include the subnet mask in routing updates. When an update is sent, the packet contains only the major network information depending on whether it is a class A,B, or …
300-100 Cisco exam prep technologies
October 15, 2018
Cisco Network Fundamentals // Static Routes
Welcome to the first of my Cisco Network Fundamentals series I will be covering all sorts from the exam topics, including live simulation scenarios. Long reads have their place but I wanted these to be something you could quickly review on a coffee break. Also, even though the primary focus it exam prep, my hope …
300-100 Cisco exam prep technologies
October 15, 2018
Cisco Network Fundamentals // Dynamic Routing
Dynamic Routing These protocols can dynamically respond to changes in the network. The routing protocol is configured on each router and the routers learn about both each other and remote networks. Examples of modern dynamic routing protocols include: • RIP v1,2 (ok, maybe this isn’t very “modern”) • EIGRP • IS-IS • OSPF • BGP Distance Vector vs. Link-State Distance Vector When …
design gadgets technologies
October 15, 2018
SergeantClip
The Phone Call One morning, around 2am, I received a call from my manager – “I know you’re not on call and so you know I wouldn’t be calling you if it wasn’t urgent but…….”. I was a network engineer for a long time and those words for me are like the Bat-signal – I …
business technologies
October 15, 2018
What’s the difference between VPN’s, VRF’s and MPLS
In some business circles i.e. project managers, solutions architects, blue-sky thinkers or the wizards of light bulb moments, your company WAN (Wide Area Network) is sometimes referred to as VRF, MPLS, VPN, VFR’s or ‘that network thing”. So I thought I’d try to explain it all to a variety of audiences. This is a high-level …