Urpf Strict Mode - Cisco Catalyst 4500 Series Configuration Manual

Chapter 1 Product Overview
Starting with Cisco IOS Release 12.2(40)SG, the Catalyst 4500 series switch allows suppression of
broadcast and multicast traffic on a per-port basis.
For information on configuring broadcast suppression, see

uRPF Strict Mode

The uRPF feature mitigates problems caused by the introduction of malformed or forged (spoofed) IP
source addresses into a network by discarding IP packets that lack a verifiable IP source address. uRPF
deflects denial-of-service (DoS) and distributed denial-of-service (DDoS) attacks by forwarding only
packets that have source addresses that are valid and consistent with the IP routing table. This helps to
protect the network of the customer, the ISP, and the rest of the Internet. When using uRPF in strict mode,
the packet must be received on the interface that the router uses to forward the return packet. uRPF strict
mode is supported for both IPv4 and IPv6 prefixes.
For information on configuring broadcast suppression, see
Path Forwarding."
Utilities
Supported utilities include the following:
Layer 2 Traceroute
Layer 2 traceroute allows the switch to identify the physical path that a packet takes from a source device
to a destination device. Layer 2 traceroute supports only unicast source and destination MAC addresses.
For information about Layer 2 Traceroute, see
Time Domain Reflectometry
Time Domain Reflectometry (TDR) is a technology used for diagnosing the state and reliability of
cables. TDR can detect open, shorted, or terminated cable states. The calculation of the distance to the
failure point is also supported.
For information about TDR, see
Debugging Features
The Catalyst 4500 series switch has several commands to help you debug your initial setup. These
commands are included in the following command groups:
•
•
For more information, refer to the Catalyst 4500 Series Switch Cisco IOS Command Reference.
OL-25340-01
platform
debug platform
Chapter 8, "Checking Port Status and Connectivity."
Chapter 8, "Checking Port Status and Connectivity."
Software Configuration Guide—Release IOS XE 3.3.0SG and IOS 15.1(1)SG
Chapter 54, "Configuring Storm Control."
Chapter 34, "Configuring Unicast Reverse
Security Features
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