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.
| 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. |
If you do not specify a VR or VRF, the current VR context is used.
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.
The following example adds a blackhole default route into the routing table:
configure iproute add blackhole default
This command was first available in ExtremeXOS 10.1.
The ipv4 keyword was added in ExtremeXOS 11.2.
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.