configure iproute add blackhole ipv4 default

configure iproute add blackhole ipv4 default {multicast | multicast-only | unicast | unicast-only} {vr vrname}

Description

Adds a default blackhole route to the routing table. All traffic destined for an unknown IP destination is silently dropped, and no ICMP message is generated.

Syntax Description

multicast Adds the default blackhole route to the multicast routing table.
multicast-only Adds the default blackhole route to the multicast routing table. This option is provided for backward compatibility with releases prior to ExtremeXOS Release 12.1.
unicast Adds the default blackhole route to the unicast routing table.
unicast-only Adds the default blackhole route to the unicast routing table. This option is provided for backward compatibility with releases prior to ExtremeXOS Release 12.1.
vrname Specifies the VR or VRF to which the route is added.

Default

If you do not specify a VR or VRF, the current VR context is used.

Usage Guidelines

While a default route is for forwarding traffic destined to an unknown IP destination, and a blackhole route is for discarding traffic destined to a specified IP destination, a default blackhole route is for discarding traffic to the unknown IP destination.

Using this command, all traffic with an unknown destination is discarded.

The default blackhole route is treated like a permanent entry in the event of a switch reset or power off/on cycle. The default blackhole route‘s origin is "b" or "blackhole" and the gateway IP address for this route is 0.0.0.0.

Example

The following example adds a blackhole default route into the routing table:

configure iproute add blackhole default

History

This command was first available in ExtremeXOS 10.1.

The ipv4 keyword was added in ExtremeXOS 11.2.

Platform Availability

This command is available on ExtremeSwitching X435, X440-G2, X450-G2, X460-G2, X465, X590, X620, X670-G2, X690, X695, X870, 5320, 5420, and 5520 series switches.