35-43
Catalyst 3750 Switch Software Configuration Guide
OL-8550-02
Chapter 35 Configuring IP Unicast Routing
Configuring BGP
Configuring BGP
The Border Gateway Protocol (BGP) is an exterior gateway protocol used to set up an interdomain
routing system that guarantees the loop-free exchange of routing information between autonomous
systems. Autonomous systems are made up of routers that operate under the same administration and
that run Interior Gateway Protocols (IGPs), such as RIP or OSPF, within their boundaries and that
interconnect by using an Exterior Gateway Protocol (EGP). BGP Version 4 is the standard EGP for
interdomain routing in the Internet. The protocol is defined in RFCs 1163, 1267, and 1771. You can find
detailed information about BGP in
Internet Routing Architectures,
published by Cisco Press, and in the
“Configuring BGP” chapter in the
Cisco IP and IP Routing Configuration Guide
.
For details about BGP commands and keywords, see the “IP Routing Protocols” part of the
Cisco IOS
IP Command Reference, Volume 2 of 3: Routing Protocols, Release 12.2
.
For a list of BGP commands
that are visible but not supported by the switch, see
Appendix D, “Unsupported Commands in
Cisco IOS Release 12.2(35)SE.”
Routers that belong to the same autonomous system (AS) and that exchange BGP updates run
internal
BGP
(IBGP), and routers that belong to different autonomous systems and that exchange BGP updates
run
external BGP
(EBGP). Most configuration commands are the same for configuring EBGP and IBGP.
The difference is that the routing updates are exchanged either between autonomous systems (EBGP) or
within an AS (IBGP).
Figure 35-5
shows a network that is running both EBGP and IBGP.
Figure 35-5
EBGP, IBGP, and Multiple Autonomous Systems
Before exchanging information with an external AS, BGP ensures that networks within the AS can be
reached by defining internal BGP peering among routers within the AS and by redistributing BGP
routing information to IGPs that run within the AS, such as IGRP and OSPF.
show ip eigrp topology
[
autonomous-system-number
] |
[[
ip-address
]
mask
]]
Display the EIGRP topology table for a given process.
show ip eigrp traffic
[
autonomous-system-number
]
Display the number of packets sent and received for all or a
specified EIGRP process.
Table 35-8
IP EIGRP Clear and Show Commands (continued)
Command
Purpose
AS 100
74775
AS 200
129.213.1.2
175.220.212.1
129.213.1.1
192.208.10.2
AS 300
EBGP
EBGP
192.208.10.1
175.220.1.2
IBGP
Router B
Router A
Router D
Router C
Содержание 3750G - Catalyst Integrated Wireless LAN Controller
Страница 80: ...1 28 Catalyst 3750 Switch Software Configuration Guide OL 8550 02 Chapter 1 Overview Where to Go Next ...
Страница 606: ...27 8 Catalyst 3750 Switch Software Configuration Guide OL 8550 02 Chapter 27 Configuring UDLD Displaying UDLD Status ...
Страница 670: ...31 18 Catalyst 3750 Switch Software Configuration Guide OL 8550 02 Chapter 31 Configuring SNMP Displaying SNMP Status ...
Страница 1048: ...41 20 Catalyst 3750 Switch Software Configuration Guide OL 8550 02 Chapter 41 Configuring MSDP Monitoring and Maintaining MSDP ...
Страница 1086: ...43 26 Catalyst 3750 Switch Software Configuration Guide OL 8550 02 Chapter 43 Troubleshooting Using the crashinfo Files ...
Страница 1104: ...B 4 Catalyst 3750 Switch Software Configuration Guide OL 8550 02 Appendix B Supported MIBs Using FTP to Access the MIB Files ...