Overview: This post covers a few important switching concepts that describe how a switch operates including MAC learning and aging, frame switching, frame flooding and the MAC address table. Study Notes: 2.1.a MAC learning To switch frames between LAN ports efficiently, the switch maintains an address table called the MAC table. When the switch receives […]
Overview: IPv6 address types consist of unicast and multicast addresses along with anycast addresses. With IPv6, an interface is expected to have multiple addresses. It also listens to various multicast addresses. IPv4 addresses are either unicast, multicast or broadcast. In IPv6, broadcast addresses no longer exist. Study notes: Unicast – uniquely identifies an interface. […]
Overview: IPv6 Stateless address autoconfiguration is similar to DHCP in IPv4. Routers running IPv6 can give the network prefix and gateway address to clients looking for an IPv6 address. The device needs a global IPv6 address to be able to connect to the network (and internet). IPv6 stateless autoconfiguration is a way for a device […]
Overview: IPv6 addressing was designed to address the deficiencies in IPv4. It is based on 128-bit hexadecimal IP addresses, which provide a much greater amount of addresses (3.4×10^38 or 340 undecillion) while still meeting requirements to be heirarchical and scalable. So what happened to IPv5? I always assumed IPv4 was so because it used four […]
Overview: IPv6 addressing is designed differently than IPv4. Subnetting is used in IPv4 to more efficiently use the small number of available addresses. IPv6 has a large enough address space without subnetting to accommodate devices for the foreseeable future. The local area subnet always uses 64 bits for the routing prefix and 64 bits for […]
Overview: Private IPs were originally meant as a more secure means of providing IPv4 addresses to devices because private IPs are not routable over the internet. It turns out that private IPs also came in handy as a means to save valuable public IPv4 address space. Without private IPv4 addressing, we would not have anymore […]
Overview: Understand the differences between IPv4 address types including unicast, broadcast and multicast IPv4 addresses Study Notes: Understand the different IPv4 address types. Loopback – this IP points back to the device’s TCP/IP stack. Pinging it tells you whether TCP/IP has been installed and is running. Layer 2 broadcasts – Layer 2 broadcast traffic stays […]
Overview: Subnetting can be a challenge to learn initially. Instead of trying to write yet another lesson on subnetting I thought I would just include a few good references and create a lab where you can test your skills. I will urge you to watch different YouTube videos on subnetting and read different materials on […]
Overview: Understand troubleshooting methodologies and approaches to efficiently resolve network issues. Study Notes: Troubleshooting methodology Define the problem Gather information Analyze information Eliminate potential causes Propose hypothesis Test hypothesis Solve problem and document solution Approach: Top-down method: – start at the top of the OSI model Bottom-up method: start at the bottom of the […]
Overview: Understand cabling types based on their implementation. In other words, certain cables are used for certain situations. Use the wrong cable and it’s not going to work. Unless you get saved by the smarts in the device. Most network devices these days have an autodetect function, which understands if there is a straight-through or […]
