-140
Command Usage
• Split horizon never propagates routes back to an interfac e from which
they have been acquired.
• Poison reverse propagates routes back to an interface port from which
they have been acquired, but sets the distance-vector metrics to infinity.
(This provides faster convergence.)
Example
This example propagates routes back to the source using poison-reverse.

ip rip authentication key

Use this command to enable authentication for RIPv2 packets and to
specify the key that must be used on an interface. Use the no form to
prevent authentication.
Syntax
ip rip authentication key key-string
no ip rip authentication
key-string - A password used for authentication.
(Range: 1-16 characters, case sensitive)
Command Mode
Interface Configuration (VLAN)
Default Setting
No authentication
Command Usage
• This command can be used to restrict the interfaces that can exchange
RIPv2 routing information. (Note that this command does not apply
to RIPv1.)
• For authentication to function properly, both the sending and receivin g
interface must be configured with the same password.
Console(config)#interface vlan 1
Console(config-if)#ip split-horizon poison-reverse
Console(config-if)#