UDP is often used for traffic that doesn’t need the reliability and security of TCP, such as VOIP applications. However, many modern applications utilize UDP for quick packet transfer, with resiliency and security handled at higher layers of the OSI model; QUIC is a prominent example of this approach.
The UDP header features the same source and destination ports but lacks sequence numbers or control bits, resulting in reduced overhead and faster data transmission.
Due to the absence of features like the 3-Way Handshake, UDP is more susceptible to spoofing.
Devices connect to a Local Area Network (LAN) through a switch, which uses MAC (Media Access Control) addresses for communication instead of the more common IP addresses. Switches manage traffic within LANs, such as home networks or organizational branches. While MAC addresses are intended to be unique, they can be modified by anyone with administrative rights.
A MAC address consists of six octets, like FC:F8:AE:12:34:56. The first three octets, known as the Organizational Unique Identifier (OUI), identify the device manufacturer—e.g., Intel Corporate—while the remaining three octets are assigned by the manufacturer. MAC addresses can be looked up on sites like https://www.adminsub.net/mac-address-finder/intel.
ARP (Address Resolution Protocol) allows computer systems to map IP addresses to their corresponding MAC addresses, forwarding traffic to the Default Gateway, and checking the ARP cache for recent resolutions when communicating within a LAN; the ARP cache can be viewed using the command arp -a on both Linux and Windows.
| Alice: Does anyone know the MAC address of 192.168.10.10? Bob: Sure thing Alice, here is my MAC Address. |
VLAN, also known as Private VLANs, allows a switch to embed tags (or a VLAN ID) within network frames. This enables multiple switches to ensure that devices on the LAN can only communicate with others that share the same VLAN ID.