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

Hardware configuration mode

Usage Guidelines

This command is applicable only on Layer 3 physical, port-channel, and VE interfaces. On a Layer 3 interface, uRPF is enabled by configuring an uRPF mode on that interface and can be modified to a different mode dynamically on that interface.

On the SLX 9540, RPF mode is not supported when OptiScale is enabled.

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

Neither loose mode nor strict mode includes the default route in the Source IP (SIP) lookup.

Strict mode is not supported for ECMP routes or for IP over MPLS (IPoMPLS).

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