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 5320, 5420, 5520, and 5720 series switches.