interfaces <interface> ipv6 ripng split-horizon
Configures split-horizon and split-horizon poison-reverse on an interface that is running RIPng.
Split-horizon is enabled.
- interface
- Mandatory. A type of interface. For detailed keywords and arguments that can be specified as interface types, refer to Supported Interface Types.
- disable
- Disables split-horizon on the specified interface.
- poison-reverse
- Enables poison-reverse on the specified interface.
Configuration mode
interfaces interface {
ipv6 {
ripng {
split-horizon {
disable
poison-reverse
}
}
}
}
Use this command to disable split-horizon or enable split-horizon poison-reverse on an interface that is running RIPng.
Split-horizon is a stability feature that reduces the possibility of network loops, particularly when links become disconnected. It stops an interface from including in its network updates to any routes that it learned from that interface. Split-horizon is effective at preventing loops between routers that are directly connected to each other, and it speeds convergence when network conditions change. Split-horizon is the default setting in RIPng.
Poison-reverse is a variation of split-horizon. When an interface that has poison-reverse enabled detects a link that is down, it increases the metric for that route to 16 and propagates that information in its next update. Because 15 is the largest number of hops that can be reached on a RIPng network, increasing the metric to 16 renders the route unreachable as far as downstream RIPng routers are concerned. This is called “poisoning” the route. Poison-reverse is useful for propagating information about bad routes to routers that are downstream but not immediate neighbors, where split-horizon is ineffective.
When this option is enabled, the router includes the route in announcements to the neighbor from which it was learned. When this option is disabled, the router omits the route from announcements to the neighbor from which it was learned.
Use the set form of this command to configure split-horizon and split-horizon poison-reverse on an interface that is running RIPng.
Use the show form of this command to display the current configuration of split-horizon.