ICND1 100-105

Hub

Answer explanation

Multi-port repeater Has one collision domain and one broadcast domain

Network Segmentation

Answer explanation

Breaking up a large network into smaller, more manageable ones

Things that commonly cause LAN traffic congestion

Answer explanation

Too many hosts in a collision/broadcast domain Broadcast storms Too much multicast traffic Low bandwidth Adding hubs for connectivity to the network A bunch of ARP broadcasts

WAN

Answer explanation

Wide Area Network Provides connection the rest of the world

Router

Answer explanation

Layer 3 device Connect multiple network segments to create an internetwork Connect a network to a WAN Doesn't forward broadcast or multicast packets by default Can use access lists (ACLs) for added security by limiting what types of packets can go on each interface Can provide layer 2 bridging functions if necessary Provides connections between VLANs (b/c routers are layer 3 devices) Breaks up collision domains Can filter the network based on layer 3 info (i.e. IP address) Provides communication between VLANs Functionality of a router: - Packet switching - Packet filtering - Internetwork communication - Path selection

Collision Domain

Answer explanation

A network scenario in which one device sends a packet out on a network segment and every other device on that same segment is forced to pay attention no matter what. If a different device tries to transmit at the same time, they both have to retry, one at a time (bad, not efficient)

Internetwork

Answer explanation

Is created when a router connects two or more networks together, and use logical addressing (IP or IPv6)

Routing Table

Answer explanation

A "map" of an internetwork Network Addresses: Protocol-specific, address of the destination network Interface: The exit interface a packet needs to go through to get to a certain network Metric: Distance to the network (calculated differently for different protocols)

Bridge

Answer explanation

Similar to a switch, deprecated (can't buy a physical bridge anymore) Breaks up collision domains on a LAN

Switch

Answer explanation

Sometimes referred to as a "bridge" (which would be a layer 2 switch) Breaks up collision domains (each port on a switch is a separate collision domain) A layer 3 switch is effectively a router (i.e. Cisco 3560 switch) An example of a layer 2 switch could be the Cisco 2950 Doesn't break up broadcast domains by default (can be done through a VLAN) Filters network traffic using hardware (MAC) addresses