ipv6 route null
Configures an IPv6 null route for discarding traffic.
Syntax
ipv6 route
dest-ipv6-prefix/prefix-length
null 0
[
metric
]
[
distance
number
]
[
tag
tag-number
]
no ipv6 route
dest-ipv6-prefix/prefix-length
null 0
Command Default
No IPv6 static route is configured by default.
Parameters
-
dest-ipv6-prefix
- Destination IPv6 prefix in hexadecimal with 16-bit values between colons, as specified in RFC 2373.
-
prefix-length
- A decimal value specifying the length of the IPv6 address prefix.
-
next-hop-ipv6-address
- IPv6 address of the next-hop gateway.
-
null 0
- Causes packets to the selected destination to be dropped by shunting them to the "null 0" interface. (This is the only available option.)
-
ethernet
slot/port
- Specifies the Ethernet slot and port.
-
metric
- Specifies a value that the Layer 3 switch uses to compare this route to other static routes in the IPv6 static route table that have the same destination. The metric applies only to routes that the Layer 3 switch has already placed in the IPv6 static route table. Two or more routes to the same destination with the same metric will load share (as in ECMP load sharing). The range is from 1 through 16. The default is 1.
-
distance
number
- Specifies an administrative distance. The range is from 1 through 254. The default is 1. This is a value that the Layer 3 switch uses to compare this route with routes from other route sources that have the same destination. By default, static routes take precedence over routes learned by routing protocols. To choose a dynamic route over a static route, configure the static route with a higher administrative distance than the dynamic route. A distance of 255 is considered unreachable.
-
tag
- Specifies a tag value for the route. The route tag can be used for route redistribution to routing protocols by means of route maps (as in IPv4 static route redistribution).
- tag-number
- A number from 0 through 4294967295. The default is 0.
Modes
Global configuration mode
VRF configuration mode
Usage Guidelines
Use the
no form of the command with the same parameters to remove the null route.
Related commands:
- ipv6 route
- ipv6 route
next-hop-vrf
Examples
The following example creates a primary route to all 2001 : DB8 : : 0/32 destinations through virtual interface (ve) 3. The primary route has the default cost metric of 1. The example aslo creates an alternative null route (with a cost metric of 2) to drop packets when the primary route is not available.
device# configure terminal
device(config)# ipv6 route 2001 : DB8 : : 0/32 fe80::1 ve 3
device(config)# ipv6 route 2001 : DB8 : : 0/32 null 0 2
