Ethernet Fundamentals Flashcards
10BASE-T
UTP
● Maximum speed: 10 Mbps
● Maximum distance: 100 meters
Deterministic
Deterministic
● Very organized and orderly
● Need an electronic token to transmit
● For example, Token Ring networks
Contention-based
Contention-based
● Very chaotic
● Transmit (almost) whenever you want
● For example, Ethernet networks
CSMA/CD
Carrier Sense Multiple Access/ Collision Detect (CSMA/CD)
▪ ETHERNET devices transmit based on a principle called carrier sense multiple access/collision detect (CSMA/CD)
▪ Carrier sense
● Listen to the wire, verify it is not busy
▪ Multiple access
● All devices have access at any time
▪ Collision detect
● If two devices transmit at the same time, a collision occurs
● Back off, wait a random time, and try again
802.3ad
Link Aggregation
▪ Congestion can occur when ports all operate at the same speed
▪Allows for combination of multiple physical connections into a single logical connection Bandwidth available is increased and the congestion is minimized or prevented
PoE 802.3af, PoE+ 802.3at
▪ Supplies electrical power over Ethernet
● Requires CAT 5 or higher copper cable
● Provides up to 15.4 watts of power to device
● PoE+ provides up to 25.5 W of power to device ▪ Two device types
● Power Sourcing Equipment (PSE)
● Powered Device (PD)
802.1x
User Authentication
▪ For security purposes, switches can require users to authenticate themselves before gaining access to the network
OOB
Out-of-band (OOB) management involves keeping all network configuration devices on a separate network
HSRP
▪ Hot Standby Router Protocol (HSRP) uses virtual IP and MAC addresses to provide a “active router” and a “standby router”
● HSRP is a Cisco-proprietary protocol
● If Active is offline, then standby answers
GLBP
Gateway Load Balancing Protocol (GLBP)
First Hop Redundancy
● Cisco-proprietary protocol
VRRP
Virtual Router Redundancy Protocol (VRRP)
First Hop Redundancy
● Open-source protocol
CARP
Common Address Redundancy Protocol (CARP)
First Hop Redundancy
● Open-source protocol
STP
Spanning Tree Protocol (STP) (802.1D)
▪ Permits redundant links between switches and prevents looping of network traffic
100BASE-TX
CAT 5 or higher
100 Mbps
100m
1000BASE-TX
CAT 6 or higher
1 Gbps
100m
1000BASE-SX
MMF
1 Gbps
220 m
100 BASE-LX
SMF
1 Gbps
5 km
1000BSE-ZX
SMF
1 Gbps
70km
Hub
Same Collision Domain
Bridge
Separates Collisoin Domains
Switch
Each port separates Collision Domain
Router
Separates Broadcast Domain
802.1x
User Authentication
▪ For security purposes, switches can require users to authenticate themselves before gaining access to the network
HSRP
Hot Standby Router Protocol (HSRP) uses virtual IP and MAC addresses to provide a “active router” and a “standby router”
FIRST HOP REDUNDANCY
● HSRP is a Cisco-proprietary protocol
● If Active is offline, then standby answers
STP
Spanning Tree Protocol (STP) (802.1D) ▪ Permits redundant links between switches and prevents looping of network traffic
SPB
Shortest Path Bridging (SPB) is used instead of STP for larger network environments
Root Bridge
Root bridge
● Switch elected to act as a reference point for a spanning tree
● Switch with the lowest bridge ID (BID) is elected as the root bridge
● BID is made up of a priority value and a MAC address (with the lowest value considered root)
Root Port
Root Port
● Every non-root bridge has a single root port
● Port closest to the root bridge in terms of cost
● If costs are equal, lowest port number is chosen
Port States
Blocking, Listening, Learning, Forwarding
BPDU
Bridge Protocol Data Units
Frames that contain information about the spanning tree protocol. A switch sends BPDUs using a unique source MAC address from its origin port to a multicast address with destination MAC
Link Costs
▪ Associated with the speed of a link
▪ Lower the link’s speed, the higher the cost
802.1q
VLAN Trunking
▪ Multiple VLANs transmitted over the same physical cable ▪ VLANs are each tagged with 4-byte identifier
● Tag Protocol Identifier (TPI)
● Tag Control Identifier (TCI)
▪ One VLAN is left untagged
Called the Native VLAN
Proxy Server
▪ Device that makes a request to external network on behalf of a client
▪ Used for security to perform content filtering and logging
▪ Workstation clients are configured to forward their packets to a proxy server
NAS
Network Attached Storage (NAS)
● Disk storage is delivered as a service over TCP/IP
SAN
Storage Area Network (SAN)
● Specialized LAN designed for data transfer/storage
● Transfers data at block level with special protocol
● Fibre Channel (FC) o Special purpose hardware providing 1-16 Gbps
FCoE
Fibre Channel over Ethernet (FCoE)
Removes need for specialized hardware
Runs over your Ethernet networks
iSCSI
SCSI (IP Small Computer System Interface)
o Lower cost, built using Ethernet switches (<10 Gbps)
o Relies on configuration allowing jumbo frames over the network
Infiniband
Infiniband (Virtualized Storage)
▪ Switched fabric topology for high-performance computing
▪ Very high throughput (>600 Gbps) with very low latency (0.5 µsec)
▪ Direct or switched connection between servers and storage systems
SDN
Software-Defined Networking (SDN)
▪ Provides the administrator with an easy-to-use front end to configure physical and virtual devices throughout the network
▪ All the configurations are automatically done
▪ Provides administrator and overview of the entire network
