Cisco Systems 3130 User Manual
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Cisco Catalyst Blade Switch 3130 for Dell Software Configuration Guide
OL-13270-01
Chapter 38 Configuring IP Unicast Routing
Configuring OSPF
Configuring Split Horizon
Routers connected to broadcast-type IP networks and using distance-vector routing protocols normally
use the split-horizon mechanism to reduce the possibility of routing loops. Split horizon blocks
information about routes from being advertised by a router on any interface from which that information
originated. This feature can optimize communication among multiple routers, especially when links are
broken.
use the split-horizon mechanism to reduce the possibility of routing loops. Split horizon blocks
information about routes from being advertised by a router on any interface from which that information
originated. This feature can optimize communication among multiple routers, especially when links are
broken.
Note
In general, we do not recommend disabling split horizon unless you are certain that your application
requires it to properly advertise routes.
requires it to properly advertise routes.
Beginning in privileged EXEC mode, follow these steps to disable split horizon on the interface:
To enable the split horizon mechanism, use the ip split-horizon interface configuration command.
Configuring OSPF
This section briefly describes how to configure Open Shortest Path First (OSPF). For a complete
description of the OSPF commands, see the “OSPF Commands” chapter of the Cisco IOS IP Command
Reference, Volume 2 of 3: Routing Protocols, Release 12.2.
description of the OSPF commands, see the “OSPF Commands” chapter of the Cisco IOS IP Command
Reference, Volume 2 of 3: Routing Protocols, Release 12.2.
Note
OSPF classifies different media into broadcast, nonbroadcast, and point-to-point networks. The switch
supports broadcast (Ethernet, Token Ring, and FDDI) and point-to-point networks (Ethernet interfaces
configured as point-to-point links).
supports broadcast (Ethernet, Token Ring, and FDDI) and point-to-point networks (Ethernet interfaces
configured as point-to-point links).
OSPF is an Interior Gateway Protocol (IGP) designed expressly for IP networks, supporting IP
subnetting and tagging of externally derived routing information. OSPF also allows packet
authentication and uses IP multicast when sending and receiving packets. The Cisco implementation
supports RFC 1253, OSPF management information base (MIB).
subnetting and tagging of externally derived routing information. OSPF also allows packet
authentication and uses IP multicast when sending and receiving packets. The Cisco implementation
supports RFC 1253, OSPF management information base (MIB).
The Cisco implementation conforms to the OSPF Version 2 specifications with these key features:
•
Definition of stub areas is supported.
•
Routes learned through any IP routing protocol can be redistributed into another IP routing protocol.
At the intradomain level, this means that OSPF can import routes learned through EIGRP and RIP.
OSPF routes can also be exported into RIP.
At the intradomain level, this means that OSPF can import routes learned through EIGRP and RIP.
OSPF routes can also be exported into RIP.
Command
Purpose
Step 1
configure terminal
Enter global configuration mode.
Step 2
interface interface-id
Enter interface configuration mode, and specify the interface to
configure.
configure.
Step 3
ip address ip-address subnet-mask
Configure the IP address and IP subnet.
Step 4
no ip split-horizon
Disable split horizon on the interface.
Step 5
end
Return to privileged EXEC mode.
Step 6
show ip interface interface-id
Verify your entries.
Step 7
copy running-config startup-config
(Optional) Save your entries in the configuration file.