IPv4 Protocol field tells the receiver what kind of protocol message is inside the IP datagram’s payload. So, no—ICMP, IGMP, OSPF, TCP, and UDP are not flags inside the payload. The IPv4 header contains a small numeric field called Protocol, and that number identifies how to interpret the payload. For example: If the Protocol field …
Category: Computer Networks
Sep 25
Do routers in the Internet Core Use MAC address?
Yes — if the link between two routers is Ethernet, the packet is carried from one router to the next inside an Ethernet frame that uses MAC addresses for that particular hop. But the important distinction is: Routers decide where to send the packet using Layer 3 information such as the IP destination (or sometimes …
Sep 10
The Hidden Firewall: How Public Wi-Fi Keeps Your Devices Apart
The Hidden Firewall: How Public Wi-Fi Keeps Your Devices Apart : From AI tools as is Have you ever sat in a crowded coffee shop, connected to the free Wi-Fi, and wondered: If dozens of us are on the exact same network, why can’t I see anyone else’s computer? It’s a valid question. When you …
Sep 10
One Physical Switch, Multiple VLANs: How VLANs Work, How to Configure Them, and Where IP Subnets Fit In
One Physical Switch, Multiple VLANs: How VLANs Work, How to Configure Them, and Where IP Subnets Fit In From AI tools as IS. A single managed Ethernet switch can behave as though it were several independent switches. This is the basic idea behind a VLAN — Virtual Local Area Network. Suppose an organization has one …
Sep 10
Network Devices, VLANs, Subnets, Layer 2 and Layer 3 Switches, and Routers
Network Devices, VLANs, Subnets, Layer 2 and Layer 3 Switches, and Routers From AI tools as IS. Modern computer networks are built from several different kinds of devices and several different kinds of logical boundaries. This can become confusing because terms such as switch, router, VLAN, subnet, LAN, Layer 2, and Layer 3 are closely …
Sep 10
Voice Networks and Data Networks: From Analog Telephone Circuits to Modern IP Communication
Voice Networks and Data Networks: From Analog Telephone Circuits to Modern IP Communication From AI tools as IS. For much of the history of telecommunications, a voice network and a data network were genuinely different kinds of networks. Telephone networks were built primarily to carry human conversations. Computer networks were built primarily to exchange data …
Sep 09
PAN, LAN, CAN, MAN, and WAN: Understanding Network Types by Geographic Scope
PAN, LAN, CAN, MAN, and WAN: Understanding Network Types by Geographic Scope REf: AI Tools as IS Computer networks are often classified according to the geographic area they cover. The most common categories are: At first glance, these categories may look like they are defined simply by distance. However, that is only partly true. There …
Sep 09
Understanding the Electromagnetic Spectrum, Radio Frequencies, and Wi-Fi
Understanding the Electromagnetic Spectrum, Radio Frequencies, and Wi-Fi Ref: AI Tools as is When we talk about Wi-Fi, cellular networks, radio, Bluetooth, satellite communication, infrared, visible light, X-rays, or gamma rays, we are talking about different parts of the same broad phenomenon: the electromagnetic spectrum. The main difference between these forms of electromagnetic radiation is …
Sep 09
How Do Cell Phones Become Part of Computer Networks?
How Do Cell Phones Become Part of Computer Networks? Ref: AI Tools as is Most people think of a computer network as a collection of laptops, desktops, servers, switches, and routers connected together through cables or Wi-Fi. But modern cell phones are also full-fledged networked computers. A smartphone becomes part of a computer network whenever …
Jun 28
Understanding Host-Only Networking in Oracle VirtualBox: Concepts, Tools, IP Addressing, DHCP, and Practical Options
Ref: Oracle VirtualBox User Guide: VirtualBox supports configurable virtual network cards per VM, host-only networking connects VMs with each other and the host while keeping them away from the outside network, and VirtualBox includes a DHCP server for host-only/internal networks. (VirtualBox) (VirtualBox) Introduction Oracle VirtualBox provides several networking modes for virtual machines. Each mode answers …
