Post on 15-May-2015
description
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Ethernet Protocols
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Protocol & Standard Function
IEEE 802.3u Fast Ethernet
IEEE 802.3z Giga Bit Ethernet
IEEE 802.1D STP (Spanning Tree Protocol)
IEEE 802.1s MISTP (Multiple Instance STP)
IEEE 802.1w RSTP (Rapid STP)
IEEE 802.1p Priority Queuing, CoS
IEEE 802.1Q VLAN (Port based, GVRP)
IEEE 802.1ad VLAN (Q-in-Q)
IEEE 802.1ah VLAN (MAC-in-MAC)
IEEE 802.3ad Link Aggregation Control Protocol (LACP)
IEEE 802.3x Flow Control and Back-pressure
IEEE 802.3ah Ethernet OAM (Discovery, Event Notif, Loopback)
IEEE 802.1ag Ethernet OAM (CFM)
ITU-T/Y.1731 Ethernet OAM (CFM, PM)
ITU-T G.8032/Y.1344 E-SPRing Ethernet Ring Protection Switch
ITU-T G.8261/Y.1361 Timing and synchronization aspects in packet networks
IEEE 1588v2 Synchronization Protocol (PTP) in packet networks
Ethernet Protocols & Main Functions
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IEEE Standards
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Frame formats for Ethernet and IEEE 802.3
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Reserved MAC Addresses
Dest. Address Assignment
01:00:5E:xx:xx:xx Group Dest. Addr. (GDA)
FF:FF:FF:FF:FF:FF Broadcast Addr.
01:80:C2:00:00:00 BPDU (STP)
01:80:C2:00:00:01 Pause frame
01:80:C2:00:00:10 All LANs Bridge Management
01:80:C2:00:00:20 GMRP
01:80:C2:00:00:21 GVRP
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DSLAMPCATU-R
ATMBay Networks
Bay Networks
BRASATM
SwitchATM
Switch
1483
Ethernet
ATM
ADSLPHYPHY
Ethernet Ethernet
ATM
ADSL
ATM
STM-1
1483
Ethernet
ATM
STM-1 PHY
Ethernet
ADSL ATM ATM
PPPoE
PPP
IP
PPPoE
PPP
IP
PVC PVC
Protocols of ATM DSLAM
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Protocols of IP DSLAM
DSLAMPCATU-R
IP
BRASRouter
1483
Ethernet
ATM
xDSLPHYPHY
Ethernet Ethernet
PHY
Ethernet
xDSL Ethernet
PPPoE
PPP
IP
PPPoE
PPP
IP
PVC1483
Ethernet
ATM
xDSL PHY
Ethernet
RouterEthernet
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802.1d STP
The primary goals of Spanning Tree are as follows:
Elimination of loops in a bridged infrastructure;
Improved scalability in a large network;
Provision of redundant paths, which can be activated
upon failure.
The Bridge Protocol exchanges Bridge Protocol Data
Units (BPDUs) in Bridged LAN communication
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Find out the Root Bridge
which has lowest cost
and eliminate looping
Root
802.1d STP Principle
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Bridge Architecture
802.1d STP Architecture
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Operation of inter-bridge protocol
802.1d STP internal operation
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Forwarding and Filtering flow chart
802.1d STP flow chart
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Learning Process: Station A sends a frame to Station B
802.1d STP example
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Complete Filtering Database is built, Station B sends a frame to Station C
802.1d STP example cont.
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IGMP Overview
Rather than Unicast and Broadcast, Multicast delivers IP packets to
just a group of hosts on the network. IGMP (Internet Group
Multicast Protocol) is a Network Layer protocol used to establish
membership in a Multicast group
Multicast IP address are Class D IP address, from 224.0.0.0 to
239.255.255.255. They are also referred to as Group Destination
Address (GDA). For each GDA, there is an associated MAC
address. This GDA MAC address is formed by
01:00:5E:XX:XX:XX, followed by the latest 23 bits of the GDA
multicast IP address in hex.
For Example :
GDA 224.10.10.10 corresponds to MAC address 01:00:5E:0A:0A:0A ,
GDA 239.255.255.255 corresponds to MAC address 01:00:5E:FF:FF:FF
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IGMP Snooping
A layer-2 switch supported IGMP snooping can passively snoop
on IGMP Query, Report and Leave packets. It checks IGMP
packets passing through it, picks out the group registration
information, and configures multicasting accordingly.
Without IGMP snooping, multicast traffic is treated in the same
manner as broadcast traffic.
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What is a Virtual VLAN?
A VLAN is a switched network that is logically segmented on an
organizational basis, by functions, project teams, or applications
rather than on a physical or geographical basis.
A VLAN can be thought of as a broadcast domain that exists
within a defined set of switches.
Why need implement VLANs ?
• LAN Segmentation
• Security
• Broadcast Control
• Performance
• Network Management
• Communication between VLANs
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LAN Segmentation
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Types of VLANs
Tag-based VLAN
Untagged VLAN
- Port based
- MAC based
- Protocol based
- IP Subnet based
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VLAN Classification
When the switch receives a frame:
If the frame is untagged, the switch classifies the frame to a port-based VLAN. VID is not concerned.
If the frame is untagged, a port VLAN identifier (PVID) can be assigned for the port. Ingress traffic is associate with the PVID, and egress traffic is with VID.
If the frame is tagged, the switch uses the tagged VLAN ID to identify the broadcasting domain of the frame.
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Port-based VLAN (1)
Easy to configure, define egress ports for each port. VLAN only governs the outgoing traffic, and unidirectional Port-based VLAN can't across different switches, but,….
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Port-based VLAN (2)
Port Egress Port
port 0 all
port 1 all
port 2 all
port 3 all
port 4 all
port 5 all
port 6 all
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Port-based VLAN (3)
Port Egress Port
port 0 5
port 1 all except 0
port 2 all except 0
port 3 all except 0
port 4 all except 0
port 5 all
port 6 all except 0
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Port-based VLAN (4)
1
2
4
3
5
7
6
8
9
Ethernet
DSL 1
DSL 2
DSL 3
DSL 4
DSL 5
DSL 6
DSL 7
DSL 8
Port-based configuration for 8 DSL ports IP DSLAM
example of port filter configuration
Port Egress Port
Ethernet all
DSL 1 E
DSL 2 E
DSL 3 E
DSL 4 E
DSL 5 E
DSL 6 E
DSL 7 E
DSL 8 E
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Tag-based VLAN Overview
TPID has a defined value of 8100 in hex. When a frame has the EtherType equal to 8100, this frame carries the tag IEEE 802.1P / 802.1P.
VLAN ID has 12 bits and allow the identification of 4096 (2^12) VLANs. Of the 4096 possible VIDs, a VID of 0 is used to identify priority frames and value 4095 (FFF) is reserved, so the maximum possible VLAN configurations are 4,094.
802.1p
802.1q
8100
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How 802.1Q VLAN works (1)
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How 802.1Q VLAN works (2)
Each physical port has a parameter
called PVID. When a untagged frame
is received, the PVID is assigned to
it.
for example, the two stations
connected to the central trunk link in
the lower part of Figure. They are
VLAN-unaware and they will be
associated to the VLAN C, because
the PVIDs of the VLAN-aware
bridges are equal to VLAN C.
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How 802.1Q VLAN works (3)
The Forwarding Process decide to forward the received frames
according to the the Filtering Database
The Filtering Database consists of static registration entries
( SVLAN table) and dynamic registration entries (DVLAN
table).
SVLAN table is manually added and maintained by the
administrator.
DVLAN table is automatically learned via GVRP protocol, and
can't be created and upgraded by the administrator
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Filtering Database
Dynamic VLAN (DVLAN) table
How 802.1Q VLAN works (4)
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GVRP
The GARP VLAN Registration Protocol (GVRP)
defines a GARP Application that provides the
VLAN registration service GVRP supports the dynamic registration of
VLAN port members within a switch and
across multiple switches. GVRP is used to communicate VLAN
registration information to other VLAN-aware
switches, so that members of a VLAN can
cover a wide span of switches in a network.
GARP MulticastRegistration
Protocol (GMRP)
GARP VLANRegistration
Protocol (GVRP)
Generic Attribute Registration Protocol (GARP)
Logical Link ControlLLC SAP 0x42
Media Access Control
Physical Layer
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How 802.1Q VLAN works (2)
example of PVID assignment
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802.1ad Double Tagging
IEEE 802.1ad Q-in-Q VLAN : The primary benefit for the service
provider is reduced number of VLANs supported for the same
number of customers. Other benefits of this feature include:
PPPoE scalability. By expanding the available VLAN space from
4096 to approximately 16.8million (4096 times 4096), the number of
PPPoE sessions that can be terminated on a given interfaceis
multiplied.
When deploying Gigabyte Ethernet DSLAM in wholesale model,
you can assign the inner VLANID to represent the end-customer
virtual circuit (VC) and assign the outer VLAN ID to represent the
service provider ID.
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802.1Q Tunneling: Tunneling is a feature designed for service
providers who carry traffic of multiple customers across their
networks and are required to maintain the VLAN and Layer 2
protocol configurations of each customer without impacting the
traffic of other customers.
Using the 802.1Q tunneling feature, service providers can use only a
single VLAN to support a customer who has multiple VLANs.
The outer tag (metro tag) containing the VLAN ID unique to each
customer
802.1ad Double Tagging -cont.
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Normal, 802.1Q, and Double-Tagged Ethernet Packet Formats
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Double Tagging -- IEEE 802.1Q (Tunneling)
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The primary goals of Link Aggregation are as follows:
- Increased bandwidth
- Increased availability
- Load sharing
IEEE 802.3ad link aggregation enables you to group Ethernet
interfaces at the physical layer to form a single link layer
interface, also known as a link aggregation group (LAG) or
Bundle. For example, if you need 450 Mbps of bandwidth to
transmit data and have only a 100-Mbps Fast Ethernet link,
creating a LAG bundle containing five 100-Mbps Fast
Ethernet links is more cost effective than purchasing a single
Gigabit Ethernet link.
802.3ad Link Aggregation
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802.3ad Link Aggregation –cont.
The Link Aggregation Control Protocol (LACP) is a
mechanism for exchanging port and system information to
create and maintain LAG bundles. The LAG bundle distributes
MAC clients across the link layer interface and collects traffic
from the links to present to the MAC clients of the LAG
bundle.
LACP that can be used for automatic communication of
aggregation capabilities between Systems and automatic
configuration of Link Aggregation.
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Interface Stack for 802.3ad Link Aggregation
After configure the LAG bundle, you can route IP traffic over it or create a VLAN over it.Figure below displays the interface stack for 802.3ad link aggregation.
After configure the LAG bundle, you can route IP traffic over it or create a VLAN over it.Figure below displays the interface stack for 802.3ad link aggregation.
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Link Aggregation - Architecture
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Link Aggregation sublayer block diagram
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Link Aggregation Control Protocol (LACP)
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Port Trunking & Fail-Over Function