The neighbor must be shut down before it can be deleted.
Use the following CLI syntax to delete a neighbor.
CLI syntax
config>router# rip
[no] group group-name
[no] neighbor ip-int-name
shutdown
Example
config>router# rip
config>router>rip# group "RIP-ALA-4"
config>router>rip>group# neighbor "to-ALA-3"
config>router>rip>group>neighbor# shutdown
config>router>rip>group>neighbor# exit
config>router>rip>group# no neighbor "to-ALA-3"
Deleting the neighbor without first shutting it down causes the following message to appear:
INFO: RIP #1101 neighbor should be administratively down - virtual router index