Chapter 2 - Concepts, Characteristics of Networking Flashcards
Network Traffic Types?
Broadcast Domain
Collision Domain
Broads Cast Domain?
Consists of all devices receiving a broadcast packet which can originate from any device.
Large # of broadcast last can reduce network bandwidth.
Can effect processing power as the broadcast is heated by every system in the broadcast domain.
Any device stops processing to listen to the broadcast to accept or discard the packet.
A router indicates boundary limit as they discard brackets
Collision Domain
Network segment where a collision can occur.
Typically Ethernet networks.
Consists of devices connected to a shared media.
If hubs are used they operate they operate at the physical layer, are not aware of addressing and broadcast data across all ports.
A switch operating and the data link layer which is swear of addressing and stops collisions occurring. It uses the MAC address to send data to the receiver only.
CSMA/CD
Carrier Sense Multiple Access/Collision Detection
Better manages and detects collisions.
Determine how network devices respond when simultaneous requests are made on the same data channel.
Attempts to re send transmission after a time interval to help reduce collision chance.
CSMA/CA
Detects and avoids collisions on a network.
Listens for collisions prior to transmitting data and informs other devices not to broadcast.
Send dummy packet for collision check.
Segmentation
Keeps traffics isolated using segmentation
Virtual LAN
Use a switch to isolate systems on a network from each other.
If needed devices and communicate between VLANS.
Trunking
Used when needing more than one switch.
It builds a logical connection between two VLANS and allows systems on different sides of switches to be in the same VLAN.
Tagging Ports
Defined by IEEE 802.1Q
Used when multiple VLANS exist per port
Directs traffic to the appropriate VLAN
Not needed if only one switch.
Port Mirroring
Configure switch ports to mirror traffic between ports.
Captures traffic between devices while mirroring
only frames containing SIP/PID
MAC Address Table
Dynamically built on the switch using MAC address of frames it receives.
Can determine port forwarding
Address Resolution Protocol (ARP) Table
Maps IP Addresses to MAC Address.
Maintains a record of MAC and corresponding IP Addresses
Can implement a switching loop
Switching loop
Sends a request to other switches if the current switch doesn’t have a MAC address in the ARP Table or is missing the address.
Spanning Tree Protocol can detect a switching loop and stop it if the switch can’t find a correct MAC address.
DMZ
De Militarised Zone
Uses a firewall which only allows ports to be open to communicate with appropriate system types.
Protects internal systems in the network. Only systems needing to be exposed to the internet are.
Hub
Physical layer device
Connects systems within a LAN or different segments.
It broads casts arriving data across all ports
No swear of addressing
Switch
Network device that filters and forwards packets between LAN segments and hosts.
Operated in the Data Link Layer
Is swear of addressing and only sends data to the receiving device
Isolated network segments using device MAC Addresses
Router
Network device that forwards packets between networks.
Operates at the networking layer
Routing protocols
Enable routers to communicate with each other with respect to the routes they Handel.
RIP
Routing Information Protocol
A distance vector protocol
Shares routing information among other networks.
- Routers maintain a routing table which lists all destinations and is shared to other routers*
- Distance Vector algorithms determine which path is best to destination.*
Is open source
RIP considers how many routers have to be crosses to the destination via best path
EIGRP
Enchanted Interior Gateway Routing Protocol (EIGRP)
Enables routers to exchange information more efficiently and maintain a copy of neighbouring routing tables.
- RIP 2 only sends changes to updates of the routing table*
- RIP doesn’t take into account the state of the fastest path*
Links State Routing Protocol
Open Shortest Path First (OSPF)
A routing protocol used to determine the best path for packets.
Replaces RIP
As a router learns of a network change it will multi cast the information to all other OSPF hosts on the network.
- this updated neighbouring routing tables*
- also takes into account the state of chosen path. If path is busy it might choose a longer route that’s the most open path.*
Boarder Gateway Protocol (BGP)
Manages how packets are routed across the internet
Connects autonomous systems
Combines distance and reach ability and queries if routers are functioning along selected path
IPv6
Default IP since vista
128bit
Implemented due IPv4 address shortage.
Supports auto config which helps correct and limitations of IPv4
Converts hexadecimal to binary
16bits of 8bites
1 to 9 for digits and A to F for letters
2001:0CD8:BC20:ED02:0000:0000:0000:0000
Condensed to
2001:CD8:BC20:ED02::
Dual stack
Enables IPv4 and IPv6 to be used at the same time.
Both 4 and 6 are enabled by default
IPv6 is fine tuned to address common communication types like VOIP and Video conferencing
IPv6 Router Advertisement
Allowing client systems to recognise that a router is present
*IPv4 required anDHCO to inform client of its IP Address, subnet and default gateway.
IPv6 Neiboure Discovery
Performs tasks like
Router discovery
Duplicates address detection
Prefix discovery
Tasteless address auto config
Traffic/Packet Shaping
Regulates network data transfers
Ensures a level of performance and QoS
Prioritises traffic and delays packets deemed less important
Priority examples
VOIP
Time sensitive data like email over printing
Buisness related traffic
Internet service provider
Tiered internet like regular and standard
QoS
Quality of Service
Measures overall network performance, transmission and error rates.
Can improve traffic shaping like packet prioritisation,
Queuing, Application classification
DiffServ
Differential Services Protocol
Specified and controls network traffic by class
Based on class traffic can get precedence like VOIP as it requires an uninterrupted data flow.
DiffServ is dependant on compels policy and rules statements when forwarding network packets.
*Avoids simple priority tagging as it can be time consuming and take up resources tagging each packet.