Networking terms - Explianed [Part 2]

Broadcast Domain - A broadcast domain, simply put, is anywhere single broadcast would enter. For example, a simple switch is one broadcast domain. If you were to split it into VLANs, it would be one broadcast domain per VLAN as the IP schemes would be different. Also, routers do not forward packets, but recreate them. For this reason, each router port is a broadcast domain. Also, Switch interfaces connected to other Switches‟ interfaces are also in the same broadcast domain. When a device sends a broadcast packet (such as an ARP request), the broadcast domain is any and every end device or intermediary interface that the broadcast packet/frame touches.

Collision Domain - A Collision domain is anywhere on the network that packets can collide with one another. Each interface on any smart device (Switch, Bridge, Firewall, and Router) is its own collision domain. They are not affected by VLANs as Collision Domains are entirely based on layer 1 whereas Broadcast Domains are Layer 2. Each “dumb” device is a collision domain. A 24 port switch will have 24 collision domains, but a 5 port Hub will have only one collision domain.

-H

Houga@entropy.cat