Cisco Catalyst 4500 Series Command Reference Guide

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Catalyst 4500 Series Switch Cisco IOS Command Reference—Release IOS XE 3.4.0SG and IOS 15.1(2)SG)
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Chapter 2 Cisco IOS Commands for the Catalyst 4500 Series Switches
ip verify unicast source reachable-via
ip verify unicast source reachable-via
To enable and configure unicast RPF checks on a IPv4 interface, use the ip verify unicast source
reachable-via command. To disable unicast RPF, use the no form of this command.
ip verify unicast source reachable-via rx allow-default
no ip verify unicast source reachable-via
Syntax Description
Defaults Disabled
Command Modes Interface configuration mode
Command History
Usage Guidelines In basic RX mode, unicast RPF ensures a source address must be reachable on the arrived interface. For
example, the source must be reachable without load balancing.
Note Unicast RPF is an input function and is applied only on the input interface of a router at the upstream
end of a connection.
Do not use unicast RPF on internal network interfaces. Internal interfaces might have routing asymmetry,
which means that there are multiple routes to the source of a packet. Apply unicast RPF only where there
is natural or configured symmetry.
Examples This example shows how to enable unicast RPF exist-only checking mode:
Switch# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)# interface gigabitethernet1/1
Switch(config-if)# ip verify unicast source reachable-via rx allow-default
Switch(config-if)# end
Switch#
rx Verifies that the source address is reachable on the interface where the packet was
received.
allow-default Verifies that the default route matches the source address.
Release Modification
12.2(40)SG Support introduced on Catalyst 4900M chassis and a Catalyst 4500 with a
Supervisor Engine 6-E.

Cisco Catalyst 4500 Series Specifications

General

Series	Catalyst 4500 Series
Category	Switch
Layer Support	Layer 2, Layer 3
Form Factor	Modular chassis
Stackable	No
Chassis Slots	3, 6, 7, 10
Power Supply Options	AC, DC
Redundancy	Power supply, Supervisor engine
Network Management	Cisco IOS Software CLI, SNMP, Cisco Prime Infrastructure
Features	Security, QoS
Port Density	Up to 384 ports per chassis
Security Features	802.1X, ACLs, DHCP Snooping, Dynamic ARP Inspection, IP Source Guard
Supervisor Engine	8-E