rpf-mode

Enables strict or loose unicast Reverse Path Forwarding (uRPF) mode on an interface.

Syntax

rpf-mode { loose | strict }

no rpf-mode

Command Default

uRPF mode is not enabled.

Parameters

strict: Specifies uRPF strict mode. For details, see the Usage Guidelines.
loose: Specifies uRPF loose mode. For details, see the Usage Guidelines.

Modes

Interface configuration mode

Usage Guidelines

This command is applicable only on Layer 3 physical, port-channel, and VE interfaces.

This command is supported only on devices based on the Broadcom DNX chipset family. For a list of such devices, see the Supported Hardware topic.

Loose mode permits a packet if the source address matches a routing table entry. Packets are dropped only if the source address is not reachable through any device interface.

Strict mode requires that a packet matches a known route entry (as described in loose mode) and also that it arrives at the interface as described in the router table next-hop information. Packets that do not match both of these criteria are dropped.

Both loose mode and strict mode include the default route in the Source IP (SIP) lookup. Strict mode is not supported for ECMP routes.

uRPF is VRF-aware.

Use the no form of the command to disable uRPF on an interface.

Examples

The following example enables uRPF in strict mode on an Ethernet interface.

device# configure terminal
device(config)# interface eth 1/58
device(conf-if-eth-1/58)# rpf-mode strict