C
HAPTER
21
| Unicast Routing
Configuring the Routing Information Protocol
– 530 –
ES-4500G Series
To coexist with a network built on multilayer switches, the subnetworks for
non-IP protocols must follow the same logical boundary as that of the IP
subnetworks. A separate multi-protocol router can then be used to link the
subnetworks by connecting to one port from each available VLAN on the
network.
C
ONFIGURING
THE
R
OUTING
I
NFORMATION
P
ROTOCOL
The RIP protocol is the most widely used routing protocol. The RIP protocol
uses a distance-vector-based approach to routing. Routes are determined
on the basis of minimizing the distance vector, or hop count, which serves
as a rough estimate of transmission cost. Each router broadcasts its
advertisement every 30 seconds, together with any updates to its routing
table. This allows all routers on the network to learn consistent tables of
next hop links which lead to relevant subnets.
Figure 334: Configuring RIP
C
OMMAND
U
SAGE
◆
Just as Layer 2 switches use the Spanning Tree Algorithm to prevent
loops, routers also use methods for preventing loops that would cause
endless retransmission of data traffic. RIP utilizes the following three
methods to prevent loops from occurring:
■
Split horizon – Never propagate routes back to an interface port
from which they have been acquired.
■
Poison reverse – Propagate routes back to an interface port from
which they have been acquired, but set the distance-vector metrics
to infinity. (This provides faster convergence.)
■
Triggered updates – Whenever a route gets changed, broadcast an
update message after waiting for a short random delay, but without
waiting for the periodic cycle.
◆
RIP-2 is a compatible upgrade to RIP. RIP-2 adds useful capabilities for
plain text authentication, multiple independent RIP domains, variable
length subnet masks, and multicast transmissions for route advertising
(RFC 1723).
◆
There are several serious problems with RIP that you should consider.
First of all, RIP (version 1) has no knowledge of subnets, both RIP
A
1
3
6
4
2
5
B
C
D
E
A
A
B
C
D
Link
Cost
0
E
1
1
3
1
0
1
2
1
2
Cost = 1 for all links
Routing table for node A
Содержание iPECS ES-4526G
Страница 1: ...USER GUIDE User Manual ES 4550G ES 4526G Managed Layer 3 Stackable GE Switch ...
Страница 38: ...CONTENTS 38 ES 4500G Series ...
Страница 58: ...SECTION I Getting Started 58 ES 4500G Series ...
Страница 70: ...CHAPTER 1 Introduction System Defaults 70 ES 4500G Series ...
Страница 84: ...CHAPTER 2 Initial Switch Configuration Managing System Files 84 ES 4500G Series Success Console ...
Страница 86: ...SECTION I Web Configuration 86 ES 4500G Series Multicast Filtering on page 413 ...
Страница 196: ...CHAPTER 6 VLAN Configuration Configuring MAC based VLANs 196 ES 4500G Series ...
Страница 204: ...CHAPTER 7 Address Table Settings Clearing the Dynamic Address Table 204 ES 4500G Series ...
Страница 228: ...CHAPTER 8 Spanning Tree Algorithm Configuring Interface Settings for MSTP 228 ES 4500G Series ...
Страница 230: ...CHAPTER 9 Rate Limit Configuration 230 ES 4500G Series Figure 106 Configuring Rate Limits ...
Страница 260: ...CHAPTER 12 Quality of Service Attaching a Policy Map to a Port 260 ES 4500G Series ...
Страница 478: ...CHAPTER 17 IP Configuration Setting the Switch s IP Address IP Version 6 478 ES 4500G Series ...
Страница 528: ...CHAPTER 20 IP Services Forwarding UDP Service Requests 528 ES 4500G Series ...
Страница 584: ...CHAPTER 21 Unicast Routing Configuring the Open Shortest Path First Protocol Version 2 584 ES 4500G Series ...
Страница 614: ...CHAPTER 22 Multicast Routing Configuring PIMv6 for IPv6 614 ES 4500G Series ...
Страница 628: ...CHAPTER 23 Using the Command Line Interface CLI Command Groups 628 ES 4500G Series ...
Страница 702: ...CHAPTER 26 SNMP Commands 702 ES 4500G Series ...
Страница 710: ...CHAPTER 27 Remote Monitoring Commands 710 ES 4500G Series ...
Страница 868: ...CHAPTER 34 Port Mirroring Commands Local Port Mirroring Commands 868 ES 4500G Series ...
Страница 890: ...CHAPTER 37 Address Table Commands 890 ES 4500G Series ...
Страница 1066: ...CHAPTER 43 LLDP Commands 1066 ES 4500G Series ...
Страница 1076: ...CHAPTER 44 Domain Name Service Commands 1076 ES 4500G Series ...
Страница 1286: ...CHAPTER 49 Multicast Routing Commands PIM Multicast Routing 1286 ES 4500G Series ...
Страница 1288: ...SECTION I Appendices 1288 ES 4500G Series ...
Страница 1293: ...APPENDIX A Software Specifications Management Information Bases 1293 ES 4500G Series UDP MIB RFC 2013 ...
Страница 1294: ...APPENDIX A Software Specifications Management Information Bases 1294 ES 4500G Series ...
Страница 1327: ...ES 4526G ES 4550G E042011 ST R01 150200000149A ...
Страница 1328: ...APRIL 2011 ISSUE 1 0 ...