ethernet - networking presentation
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ETHERNET
Presenter Viet Nguyen
Computer Networks Class – BIS2013
Professor Dr. Friedbert Kaspar – Vietnamese-German University
Ethernet – IEEE 802.3
• Introduction– An overview of Ethernet– Network topologies and Switched LAN
• Ethernet technology– Ethernet technologies and cable types– Ethernet frame
• Ethernet devices– Link-layer switch– Switches vs. Routers
• Ethernet applications– Firewall– IP Spoofing
• Summary– Ethernet and its future– References
Ethernet – Viet NguyenProf. Dr. F. Kaspar – Computer Networking –BIS2013 – Vietnamese-German University
Slide 2
INTRODUCTION
Ethernet – Viet NguyenProf. Dr. F. Kaspar – Computer Networking –BIS2013 – Vietnamese-German University
Slide 3
Overview• Move Beyond Your LAN with Ethernet Services
• Ethernet is a family of computer networking technologies for local area networks (LANs). Ethernet was commercially introduced in 1980 and standardized in 1983 as IEEE 802.3.[1] Ethernet has largely replaced competing wired LAN technologies such as token ring, FDDI, and ARCNET.
Ethernet – Viet NguyenProf. Dr. F. Kaspar – Computer Networking –BIS2013 – Vietnamese-German University
Slide 4
Overview (2)
• "Switching and 100Mbps speeds make 16Mbps technology obsolete" – the time when Token Ring technology was replaced by Ethernet. (http://www.techrepublic.com/blog/classics-rock/does-anyone-actually-still-use-token-ring/)
Ethernet – Viet NguyenProf. Dr. F. Kaspar – Computer Networking –BIS2013 – Vietnamese-German University
Slide 5
1000BASE-T
http://www.sld.co.uk/products/comms/IPPBX_schematic.jpg
10BASE5
Network Topologies
Ethernet – Viet NguyenProf. Dr. F. Kaspar – Computer Networking –BIS2013 – Vietnamese-German University
Slide 6
http://upload.wikimedia.org/wikipedia/commons/9/96/NetworkTopologies.png
Network Topologies (2)
Ethernet – Viet NguyenProf. Dr. F. Kaspar – Computer Networking –BIS2013 – Vietnamese-German University
Slide 7
Star bus - Probably the most common network
topology in use today, star bus combines elements of
the star and bus topologies to create a versatile
network environment. Nodes in particular areas
are connected to hubs (creating stars), and the
hubs are connected together along the network
backbone (like a bus network). Quite often, stars
are nested within starshttp://computer.howstuffworks.com/lan-switch2.htm
Switched Local Area Networks
Ethernet – Viet NguyenProf. Dr. F. Kaspar – Computer Networking –BIS2013 – Vietnamese-German University
Slide 8
TECHNOLOGY
Ethernet – Viet NguyenProf. Dr. F. Kaspar – Computer Networking –BIS2013 – Vietnamese-German University
Slide 9
Ethernet Technologies
Ethernet – Viet NguyenProf. Dr. F. Kaspar – Computer Networking –BIS2013 – Vietnamese-German University
Slide 10
Designation Supported Media Maximum Segment Length
Transfer Speed
Topology
100Base-TX Category5 UTP 100m 100Mbps Star,using either simple repeater hubs or Ethernet switches
100Base-FX Fiber-optic- two strands of multimode 62.5/125 fiber
412m(Half-Duplex)2000m(full-duplex)
100 Mbps(200 Mb/sfull-duplexmode)
Star(often only point-to-point)
1000Base-SX Fiber-optic- two strands of multimode 62.5/125 fiber
260m 1Gbps Star, using buffered distributor hub (or point-to-point)
1000Base-LX Fiber-optic- two strands of multimode 62.5/125 fiber or monomode fiber
440m(multimode) 5000m(single-mode)
1Gbps Star,using buffered distributor hub (or point-to-point)
1000Base-CX Twinax,150-Ohm-balanced, shielded, specialty cable
25m 1Gbps Star(or point-to-point)
1000Base-T Category5 100m 1Gbps Star
Ethernet Cable Types
Ethernet – Viet NguyenProf. Dr. F. Kaspar – Computer Networking –BIS2013 – Vietnamese-German University
Slide 11
http://www.directron.com/cableguide.html
http://academy.delmar.edu/Courses/ITNW2313/1Essentials.html
Ethernet Frame
• A data packet on an Ethernet link is called an Ethernet packet, which transports an Ethernet frame as payload.
Ethernet – Viet NguyenProf. Dr. F. Kaspar – Computer Networking –BIS2013 – Vietnamese-German University
Slide 12
802.3 Ethernet packet and frame structure
Layer PreambleStart of frame
delimiter
MAC destination
MAC source802.1Q tag (optional)
Ethertype (Ethernet II) or length
(IEEE 802.3)
Payload
Frame check
sequence(3
2-bit CRC)
Interpacketgap
7 octets 1 octet 6 octets 6 octets (4 octets) 2 octets46(42)[b]–
1500 octets4 octets 12 octets
Layer 2 Ethernet
frame← 64–1518(1522) octets →
Layer 1 Ethernet packet
← 72–1526(1530) octets →
The internal structure of an Ethernet frame is specified in IEEE 802.3-2012
http://en.wikipedia.org/wiki/Ethernet_frame
Ethernet Frame (2)
• Ethernet II framing (The most common Ethernet Frame format, type II)defines the two-octet EtherType field in an Ethernet frame that identifiesan upper layer protocol encapsulating the frame data. An EtherType valueof 0x0800 signals that the frame contains an IPv4 datagram. An EtherTypeof 0x0806 indicates an ARP frame, 0x8100 indicates an IEEE 802.1Q frameand 0x86DD indicates an IPv6 frame.
Ethernet – Viet NguyenProf. Dr. F. Kaspar – Computer Networking –BIS2013 – Vietnamese-German University
Slide 13
http://en.wikipedia.org/wiki/Ethernet_frame
IP D
atag
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Ethernet – Viet NguyenProf. Dr. F. Kaspar – Computer Networking –BIS2013 – Vietnamese-German University
Slide 14
http://www.tcpipguide.com/free/t_IPDatagramEncapsulation.htm
Sublayers of the data link layer
• Logical link control sublayer: – Multiplexing protocols transmitted over the MAC layer (when
transmitting) and decoding them (when receiving).– Providing node-to-node flow and error control
• Media access control (MAC) sublayer– provides addressing and channel access control mechanisms– The hardware that implements the MAC is referred to as
a medium access controller.– The MAC layer emulates a full-duplex logical communication
channel in a multi-point network. This channel may provide unicast, multicast or broadcast communication service.
Ethernet – Viet NguyenProf. Dr. F. Kaspar – Computer Networking –BIS2013 – Vietnamese-German University
Slide 15
http://en.wikipedia.org/wiki/Data_link_layer
Logical Link Control Services
• Ethernet
• Since bit errors are very rare in wired networks, Ethernet does not provide flow control or automatic repeat request (ARQ), incorrect packets are detected but only cancelled, not retransmitted, retransmissions rely on higher layer protocols.
• As the EtherType in an Ethernet frame using Ethernet II framing is used to multiplex different protocols on top of the Ethernet MAC header it can be seen as an LLC identifier. However, Ethernet frames lacking an EtherType have no LLC identifier in the Ethernet header, and, instead, use an IEEE 802.2 LLC header after the Ethernet header to provide the protocol multiplexing function.
• Wireless LAN: In wireless communications, bit errors are very common. In wireless networks such as IEEE 802.11, flow control and error management is part of the CSMA/CA MAC protocol, and not part of the LLC layer. The LLC sub layer follows the IEEE 802.2 standard.
• HDLC (High-Level Data Link Control): Some non-IEEE 802 protocols can be thought of as being split into MAC and LLC layers. For example, while HDLC specifies both MAC functions (framing of packets) and LLC functions (protocol multiplexing, flow control, detection, and error control through a retransmission of dropped packets when indicated), some protocols such as Cisco HDLC can use HDLC-like packet framing and their own LLC protocol.
Ethernet – Viet NguyenProf. Dr. F. Kaspar – Computer Networking –BIS2013 – Vietnamese-German University
Slide 16
http://en.wikipedia.org/wiki/Logical_Link_Control
Media access control
Ethernet – Viet NguyenProf. Dr. F. Kaspar – Computer Networking –BIS2013 – Vietnamese-German University
Slide 17
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ol According to IEEE Std 802-2001 section 6.2.3 "MAC sublayer", the primary
functions performed by the MAC layer are:
•Frame delimiting and recognition
•Addressing of destination stations (both as individual stations and as groups of
stations)
•Conveyance of source-station addressing information
•Transparent data transfer of LLC PDUs, or of equivalent information in the Ethernet
sublayer
•Protection against errors, generally by means of generating and checking frame
check sequences
•Control of access to the physical transmission medium
In the case of Ethernet, according to 802.3-2002 section 4.1.4, the functions
required of a MAC are:
•receive/transmit normal frames
•half-duplex retransmission and backoff functions
•append/check FCS (frame check sequence)
•interframe gap enforcement
•discard malformed frames
•append(tx)/remove(rx) preamble, SFD (start frame delimiter), and padding
•half-duplex compatibility: append(tx)/remove(rx) MAC address
DEVICES
Ethernet – Viet NguyenProf. Dr. F. Kaspar – Computer Networking –BIS2013 – Vietnamese-German University
Slide 18
Link-Layer Switches
• A switch receives incoming link-layer frames, filters and forwards them onto outgoing links. Switch filtering and forwarding are done with a switch table.
• A switch has self-learning property (particularly for the already-overworked network administrator) that its table is built automatically, dynamically, and autonomously.
• Switches are plug-and-play devices and require no intervention from a network administrator or user.
Ethernet – Viet NguyenProf. Dr. F. Kaspar – Computer Networking –BIS2013 – Vietnamese-German University
Slide 19
Switches vs. Routers
Ethernet – Viet NguyenProf. Dr. F. Kaspar – Computer Networking –BIS2013 – Vietnamese-German University
Slide 20
A router in that it forwards packets using MAC addresses (layer-2) whereas a router is a layer-3 packet switch.
Switches vs. Routers (2)
Ethernet – Viet NguyenProf. Dr. F. Kaspar – Computer Networking –BIS2013 – Vietnamese-German University
Slide 21
Switches Routersswitches are plug-and-play not plug-and-play. their IP addresses need to be
configuredSwitches can also have relatively high filtering and forwarding rates since switches have to process frames only up through layer 2, whereas routers have to process datagrams up through layer 3
larger per-packet processing time than switches, because they have to process up through the layer-3 fieldsrouters do not have the spanning tree restriction, they have allowed the Internet to be built with a rich topology
to prevent the cycling of broadcast frames, the active topology of a switched network is restricted to a spanning tree.
packets are not restricted to a spanning tree and can use the best path between source and destination
No firewall integrated provide firewall protection against layer-2 broadcast storms
Ethernet – Viet NguyenProf. Dr. F. Kaspar – Computer Networking –BIS2013 – Vietnamese-German University
Slide 22
Hub vs. Switch vs. Router
http://thamarai-stor.blogspot.com/2010/05/ikkks-switch-vs-router-vs-hub.html
Ethernet – Viet NguyenProf. Dr. F. Kaspar – Computer Networking –BIS2013 – Vietnamese-German University
Slide 23
http://www.cisco1900router.com/tutorial-of-differences-between-hub-bridge-switch-and-router.html
a bridge is a product that connects a local area network
(LAN) to another local area network that uses the same
protocol. Having a single incoming and outgoing port and
filters traffic on the LAN by looking at the MAC address,
bridge is more complex than hub. Bridge looks at the
destination of the packet before forwarding unlike a hub. It
restricts transmission on other LAN segment if destination
is not found.
A bridge works at the
data-link (physical
network) level of a
network, copying a
data frame from one
network to the next
network along the
communications path.
APPLICATIONS
Ethernet – Viet NguyenProf. Dr. F. Kaspar – Computer Networking –BIS2013 – Vietnamese-German University
Slide 24
Firewalls
Ethernet – Viet NguyenProf. Dr. F. Kaspar – Computer Networking –BIS2013 – Vietnamese-German University
Slide 25
http://www.vicomsoft.com/learning-center/firewalls/
Social engineering involves skills not unlike those of a confidence trickster. People are tricked into revealing sensitive information.
A firewall filters both inbound and outbound traffic.
"There are management solutions to technical problems, but no technical solutions to management problems"
Figure 9: Stateful Multilayer Inspection FirewallFigure 8: Application level Gateway
Figure 6: Packet Filtering Firewall Figure 7: Circuit level Gateway
Firewalls (2)
Ethernet – Viet NguyenProf. Dr. F. Kaspar – Computer Networking –BIS2013 – Vietnamese-German University
Slide 26
IP Spoofing
Ethernet – Viet NguyenProf. Dr. F. Kaspar – Computer Networking –BIS2013 – Vietnamese-German University
Slide 27
http://en.wikipedia.org/wiki/File:IP_spoofing_en.svg
Any router that implements
ingress filtering checks the
source IP field of IP packets it
receives, and drops packets if
the packets don't have an IP
address in the IP address block
that the interface is
connected to
SUMMARY
Ethernet – Viet NguyenProf. Dr. F. Kaspar – Computer Networking –BIS2013 – Vietnamese-German University
Slide 28
The Ethernet Summary
• The Introduction covered the market use of Ethernet and its related to the Network Layer.
• The Technology and Devices sections dive deeper to the software and supported hardware for the Ethernet: Ethernet Frame, cable types, routers and switches.
• The Application gave an example of a real world use from Ethernet knowledge.
Ethernet – Viet NguyenProf. Dr. F. Kaspar – Computer Networking –BIS2013 – Vietnamese-German University
Slide 29
Ethernet and its future
Ethernet – Viet NguyenProf. Dr. F. Kaspar – Computer Networking –BIS2013 – Vietnamese-German University
Slide 30
Report from The Future of Ethernet – Technology Exploration Forum on October 15, 2013 - October 16, 2013 at Santa Clara, CA – Interconnectedness and the Future of Ethernethttp://www.enterprisenetworkingplanet.com/netsp/interconnectedness-and-the-future-of-ethernet-1.htmlhttp://www.enterprisenetworkingplanet.com/netsp/interconnectedness-and-the-future-of-ethernet-2.html
Ethernet and its future (2)
• Vehicular Ethernet, the Internet of Things, and the Industry as an Ecosystem– From enhanced traffic management and traffic alerts drawn from live video feeds
broadcast from individual vehicles to the ability to tax cars based on their miles driven, the possible applications are endless.
• Standardizing software defined networking for interoperability– "In the past, people have talked about SDN more on an individual basis. But the Ethernet
Alliance is supporting 802 in the standardization effort, which means we really want to be able to take Vendor A, plug it into Vendor B, plug that into Vendor C, and have it all work,"
• Energy Efficient Ethernet– As networks grow and evolve, their power consumption may rise, creating additional cost
issues. The Energy Efficient Ethernet (EEE) standard for twisted pair and backplane Ethernet aims to counter that by reducing power consumption as activity drops.
• Interconnectedness and the importance of consensus-building– Addressing both the main themes D'Ambrosia mentioned—interoperability and cost
concerns—will require a general consensus and interconnectedness among diverse segments of the networking community. Other TEF 2013 panels bear this out, from the panel session that pulled leaders from 802.1, 802.3, and 802.11 up onto a stage with the chair of 802, to sessions that focused on the synergy between wired and wireless technologies and on photonic integration.
Ethernet – Viet NguyenProf. Dr. F. Kaspar – Computer Networking –BIS2013 – Vietnamese-German University
Slide 31
References
• Computer Networking A Top-Down Approach – Kurose and Ross – A product of PEASON.
• http://www.omnisecu.com/basic-networking/index.php
• http://www.ccse.kfupm.edu.sa/~marwan/COE344_T062/
• http://en.wikipedia.org/wiki/Ethernet
• The INTERNET
Ethernet – Viet NguyenProf. Dr. F. Kaspar – Computer Networking –BIS2013 – Vietnamese-German University
Slide 32
THANK YOU!
The end
Ethernet – Viet NguyenProf. Dr. F. Kaspar – Computer Networking –BIS2013 – Vietnamese-German University
Slide 33
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