Ethernet Routing Switch Ethernet Routing Switch

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28 Οκτ 2013 (πριν από 4 χρόνια και 12 μέρες)

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1
Routing Switch 2003
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Ethernet Routing Switch
Ethernet Routing Switch
by
Robert Wu
Robert Wu(吳經義)
(CTO of Accton Corporation)
rwu@accton.com.tw
March 14, 2003
2
Routing Switch 2003
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I.
I.
How to drive Layer
How to drive Layer
-
-
3 Switch
3 Switch
II. Overview of IP Routing Scheme
II. Overview of IP Routing Scheme
AGENDA
Agenda
3
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WAN
o Cisco introduced
first
router
router in 1987
FastSwitcHub-8mi
30+
20
10
5
1
100M
Tx/Rx
Full Duplex
Select/Link
PWR
Collision
Status
Util
%
Forward%
Filter%
D
e
mo
D
i
ag
Full/Half
Config
1 2 3 4 5 6 7 8
90+
70
50
35
20
10
5
1
Link
Rate %
SNMP
1X 2X 3X 4X 5X 6X 7X 8MDI-X-or-8MDI
10 M/ 100 M
The Birth of the Router
router
4
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WAN
FastSwitcHub-8mi
30+
20
10
5
1
100M
Tx/Rx
Full Duplex
Select/Link
PWR
Collision
Status
Util
%
Forward%
Filter%
D
e
mo
D
i
ag
Full/Half
Config
1 2 3 4 5 6 7 8
90+
70
50
35
20
10
5
1
Link
Rate %
SNMP
1X 2X 3X 4X 5X 6X 7X 8MDI-X-or-8MDI
10 M/ 100 M
SynOpticsintroduces
first intelligent hub, 1988
The Advent of Smart Hubs
Hub
router
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Routing Switch 2003
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WAN
First Layer 2
Backbone Switch
in 1992
Router
Router
The Advent of
Enterprise Backbone Switches
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Routing Switch 2003
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WAN
Router
Oracle Financials
Mission Critical
Applications
Peoplesoft
Router
Router
Mission Critical Applications
Move onto the Network
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Web Meets Mission Critical!
WAN
Browsers
Web-Mania
Voice-over--IP
HTML Interfaces
Oracle Financials
Mission Critical
Applications
Peoplesoft
Office 97
Intranet
Routers rapidly becoming bottleneck at the edge of networks
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0
2000000
4000000
6000000
8000000
10000000
12000000
14000000
16000000
18000000
20000000
19891991199319951997
Web Pages
Web Mania
9
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0
10
20
30
40
50
60
70
80
90
199419961998E2000E2002E
SNA
IPX
RFC
ELSE
IP
%
IP Won
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Routing Switch 2003
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20% of traffic traverses
the backbone
80% of traffic remains
in the local workgroup
Distributed Model
Old 80/20 LAN Traffic Rule
Servers
PCs
Note: Old rule has been turned upside down where 80% of traffic
remains local to the workgroup and 20% traverses the backbone
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80% of traffic traverses
the backbone
20% of traffic remains
in the local workgroup
Centralized Model
Servers
New 20/80 Rule:
20% traffic within local subnet,
80% off subnet
Key Industry Trends Changing Traffic Patterns
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Internet phenomenon redefines traffic model
10/100M NICsales have overtaken 10M only
Increase in shared databaseover LAN & WAN
Network topology flexibility
LowerSwitch price per port(< $5 ?)
Market Forces Driving Switching
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Traditional Routed Network
Traditional LAN routers that segment the network will not be
able to keep up with the performance as network communications
demands grow.
Hub
Hub
Hub
Server
Server
Server
LAN Router
14
Routing Switch 2003
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FastSwitcHub-8mi
30+
20
10
5
1
100M
Tx/Rx
Full Duplex
Select/Link
PWR
Collision
Status
Util
%
Forward%
Filter%
D
e
mo
D
i
ag
Full/Half
Config
1 2 3 4 5 6 7 8
90+
70
50
35
20
10
5
1
Link
Rate %
SNMP
1X 2X 3X 4X 5X 6X 7X 8MDI-X-or-8MDI
10 M/ 100 M
FastSwitcHub-8mi
30+
20
10
5
1
100M
Tx/Rx
Full Duplex
Select/Link
PWR
Collision
Status
Util
%
Forward%
Filter%
D
e
mo
D
i
ag
Full/Half
Config
1 2 3 4 5 6 7 8
90+
70
50
35
20
10
5
1
Link
Rate %
SNMP
1X 2X 3X 4X 5X 6X 7X 8MDI-X-or-8MDI
10 M/ 100 M
Hub
Hub
Hub
Corporate
LAN Router
Layer-2 switch
Layer-2 switch
Server
Server
Server
The standard switched network provides a fast, simple and cost-
effective alternative, but are becoming harder to controland
vulnerable to broadcast storms andredundant traffic.
Standard Switched Network
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The Layer-3 Solution
By integrating router functionality into the silicon within a
switch, Layer-3 switching offers high-speed LAN routing
in affordable solution.
Hub
Hub
Hub
Layer 3 Switch
Server
Server
Server
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Why needs LAN Router
Large, multiported Layer-2 internetworking
devices now widely available
Broadcast storms much less of a problem now
Layer-2 switches acquiring higher layer intelligence
to deal with broadcastand multicast
Router-based access lists diminishing in importance
as securitymeasure
17
Routing Switch 2003
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Layer 2
Layer 2
Layer 2
Layer-3
Layer-2+3
Architecture
Integration of Layer 2 & Layer 3
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L2
Switching
Module
L2
Switching
Module
L2
Switching
Module
L3
Switching
Module
Management
Module
80Gbps
Bus
Multi-layer Switch Implementation
19
Routing Switch 2003
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I. How to drive Layer -3 Switch
II. Overview of IP Routing Scheme
I. How to drive Layer -3 Switch
II.
Overview of IP Routing Scheme
Overview of IP Routing Scheme
Overview of IP Routing Scheme
Multi-layer Switch Implementation
20
Routing Switch 2003
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Port 1
Port 2
Port B
Port A
Port 5
Port 7
Router D
Router D
Router E
Router E
Router F
Router F
128.1.0.2
128.1.0.3
139.2.0.2
139.2.0.7
150.4.0.2
210.68.0.2
00608
00608
C001231
C001231
00608C001232
000081001235
000081001236
0010B5001239
0010B5001238
Destination MAC
00608C001231
00608C001231
Source MAC
0010B5007891
Type
0800
CRC
Ethernet Data
Source Host
210.68.0.1
Destination Host
150.4.0.1
IP Data
0010
0010
B5007891
B5007891
210.68.0.1
150.4.0.1
150.4.0.1
0010B5007894
210.68.0.0
210.68.0.0
128.1.0.0
128.1.0.0
139.2.0.0
139.2.0.0
150.4.0.0
150.4.0.0
IP Routing of Operation(1)
Subnet
Subnet
Subnet
Subnet
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Routing Switch 2003
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Port 1
Port 2
Port B
Port A
Port 5
Port 7
Router D
Router D
Router E
Router E
Router F
Router F
128.1.0.2
128.1.0.3
139.2.0.2
139.2.0.7
150.4.0.2
210.68.0.2
00608C001231
00608
00608
C001232
C001232
000081
000081
001235
001235
000081001236
0010B5001239
0010B5001238
Destination MAC
000081001235
000081001235
Source MAC
00608C001232
Type
0800
CRC
Ethernet Data
Source Host
210.68.0.1
Destination Host
150.4.0.1
IP Data
0010B5007891
210.68.0.1
150.4.0.1
0010B5007894
210.68.0.0
210.68.0.0
128.1.0.0
128.1.0.0
139.2.0.0
139.2.0.0
150.4.0.0
150.4.0.0
IP Routing of Operation(2)
Subnet
Subnet
Subnet
Subnet
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Routing Switch 2003
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Port 1
Port 2
Port B
Port A
Port 5
Port 7
Router D
Router D
Router E
Router E
Router F
Router F
128.1.0.2
128.1.0.3
139.2.0.2
139.2.0.7
150.4.0.2
210.68.0.2
00608C001231
00608C001232
000081001235
000081001236
0010B5001239
0010B5001238
Destination MAC
0010B5001238
0010B5001238
Source MAC
000081001236
Type
0800
CRC
Ethernet Data
Source Host
210.68.0.1
Destination Host
150.4.0.1
IP Data
0010B5007891
210.68.0.1
150.4.0.1
0010B5007894
210.68.0.0
210.68.0.0
128.1.0.0
128.1.0.0
139.2.0.0
139.2.0.0
150.4.0.0
150.4.0.0
IP Routing of Operation(3)
Subnet
Subnet
Subnet
Subnet
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Routing Switch 2003
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Port 1
Port 2
Port B
Port A
Port 5
Port 7
Router D
Router D
Router E
Router E
Router F
Router F
128.1.0.2
128.1.0.3
139.2.0.2
139.2.0.7
150.4.0.2
210.68.0.2
00608C001231
00608C001232
000081001235
000081001236
0010B5001239
0010B5001238
Destination MAC
0010B5007894
Source MAC
0010B51239
Type
0800
CRC
Ethernet Data
Source Host
210.68.0.1
Destination Host
150.4.0.1
IP Data
0010B5007891
210.68.0.1
150.4.0.1
150.4.0.1
0010B5007894
210.68.0.0
210.68.0.0
128.1.0.0
128.1.0.0
139.2.0.0
139.2.0.0
150.4.0.0
150.4.0.0
IP Routing of Operation(4)
Subnet
Subnet
Subnet
Subnet
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Routing Switch 2003
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The pattern matching and caching on Layer 3 switches is
similar to that of on a router. Both uses a routing protocol
and routing table to determine the best path.
However, a Layer 3 switch has the ability to reprogramthe
hardware dynamically with the current Layer-3 routing
information. This is what allows much faster packet processing.
Routers & Layer 3-Switching
Physical
Data Link
Network
1
2
3
Hubs
Switches
Routers
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Routing Switch 2003
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I. How to drive Layer -3 Switch
II. Overview of IP Routing Scheme
I. How to drive Layer -3 Switch
II.
Overview of IP Routing Scheme
Overview of IP Routing Scheme
Overview of IP Routing Scheme
Multi-layer Switch Implementation
26
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IP Table Lookup:
IP Table Lookup:
Binary Tree
Longest Matching Prefix
Route Search Algorithm
IP router must use a more complex
longest prefix matching
longest prefix matching
algorithm on the destination IP address to determine the
appropriate outbound link for each IP packet.
e.g. dest__IP : 1100 0001 1110 0001 0011 1110 1010 1111
entry__IP 1 : 1100 0001 1110 0001 0011
0000 0000 0000
mask : 1111 1111 1111 1111 1111 0000 0000 0000
entry__IP 2 : 1100 0001 1110 0001 0011 11
00 0000 0000
mask : 1111 1111 1111 1111 1111 1100 0000 0000
entry__IP 3 : 1100 0001 1110 0000 0000 0000 00
00 0000
mask : 1111 1111 1111 1111 1111 1111 1100 0000
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Routing Switch 2003
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•Provides Transparent
Router Offload-
no Network configuration
•Accelerates existing
IP/IPX Traffic to
Mega-Million pps
•Single device combines
L3 with L2 switching
•Extends life of existing routers
•Works for all IP nets
including IGRP-centric
•Real route forwarding
Router
Address Table
Host IP
Address Table
Virtual Router
IP Switched
L2 VLAN
L2 Switched
MAC Address
Table
L2 VLAN-
Subnet
L2 VLAN-
Subnet
Router
Router
Multi-
Layer
Switch
Multi-layer Switch
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QOS Policy
Control
Normal Packet
Control
Normal Packets
Expedited Packets
(QOS)
Buffer Pool
Policy-based
Switching &
Multicast
Engine
Address
Resolution
Logic
Layer 2,
Layer 3,
VLAN
PacketHdr
Analysis
& Update
Policy-based
Protocol
Engines
VLAN
Table
L2
Table
L3
Table
Media Interfaces
Route Services &
Topology
Management
Big
RISC
CPU
Switching Router Architecture
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o If (DA IP address & Subnet Mask ==
o If (DA IP address & Subnet Mask ==
Network address for a route & Subnet Mask)
Network address for a route & Subnet Mask)
-
-
IP address of next Hop used to forward the packet
IP address of next Hop used to forward the packet
-
-
IP
IP
-
-
> MAC address resolution
> MAC address resolution
-
-
forward packet with replaced MAC header and
forward packet with replaced MAC header and
decreased TTL to corresponding interface port
decreased TTL to corresponding interface port
-
-
checksum recalculation on IP header
checksum recalculation on IP header
o
o
Else continue
Else continue
search
search
through the routing table
through the routing table
Basic Routing Decision on Layer 3 Switch (I)
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Receive a packet
(layer 2 SA learning)
MAC DA=L3S port
MAC
address
address?
Dest. IP=L3S port
IP address ?
Routing table lookup
to find next hop
MAC address
Send the packet
to CPU
MAC DA/SA
replacement
Find and
TTL > 1 ?
Layer 2 switching
(using MAC DA)
TTL decrement,
recalculate IP
checksum & CRC
Send the packet
to the next hop
No
No(Layer 2 Function)
Yes
Yes
No
Yes
Layer-3 Packet Forwarding Engine(II)
31
Routing Switch 2003
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WAN
7500 Router
Layer
Layer
-
-
3 Switch
3 Switch
FastSwitcHub-8mi
30+
20
10
5
1
100M
Tx/Rx
Full Duplex
Select/Link
PWR
Collision
Status
Util
%
Forward%
Filter%
D
e
mo
D
i
ag
Full/Half
Config
1 2 3 4 5 6 7 8
90+
70
50
35
20
10
5
1
Link
Rate %
SNMP
1X 2X 3X 4X 5X 6X 7X 8MDI-X-or-8MDI
10 M/ 100 M
Layer
Layer
-
-
2 Switch
2 Switch
100
100
Mbps
Mbps
10
10
Mbps
Mbps
SNA traffic
SNA traffic
IP traffic routed
IP traffic routed
over Internet
over Internet
Layer-3 Switch
IBM
IBM
Mainframe
Mainframe
T3 to WAN
T3 to WAN
Channel connection
Channel connection
100
100
Mbps
Mbps
32
Routing Switch 2003
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Features to Look for in Layer-3 Switch
WAN interface such as T-1 & T-3
Redundant power supplies
Redundant CPU modules
Network Intrusion Detection
10 Gigabit Ethernet support
33
Routing Switch 2003
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Summary
For desktop LANs, Layer-2 switching is preferred(60%),
followed by shared-media hubs(24%).
For server farm LANs, Layer-3 switching is preferred
(56%), followed by Layer-2 switches(42%).
For LAN/campus backbones, Layer-3 switching was
preferred by an overwhelming margin(92%).
Once Layer-3 switching products were introduced, the
need to use VLANs to create multiple broadcast domains
and logical overlay networks become far less compelling,
and the VLAN type died down.
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Routing Switch 2003
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Summary(Con’t)
A Layer-2 flow is identified by the MAC addressof the
source and destination end stations.
A Layer-3 flows are identified by the source and destination
network addresses.
A Layer-4 flows are identified by the application information
in the Layer 4 header in addition to the Layer 3 information.