IP Routing Features 
Configuring RIP 
Changing the Route Loop Prevention Method 
RIP can use the following methods to prevent routing loops: 
■  Split horizon - the routing switch does not advertise a route on the same 
interface as the one on which the routing switch learned the route. 
■  Poison reverse - the routing switch assigns a cost of 16 (“infinity” or 
“unreachable”) to a route before advertising it on the same interface as 
the one on which the routing switch learned the route. This is the default. 
These loop prevention methods are configurable on an individual VLAN 
interface basis. 
Note  These methods are in addition to RIP's maximum valid route cost of 15. 
Poison reverse is enabled by default. Disabling poison reverse causes the 
routing switch to revert to Split horizon. (Poison reverse is an extension of 
Split horizon.) To disable Poison reverse on an interface, and thereby enable 
Split horizon, enter the following: 
HPswitch(config)# vlan 1 
HPswitch(vlan-1)# no ip rip poison-reverse 
Syntax:  [no] ip rip poison-reverse 
Entering the command without the “no” option will re-enable Poison reverse. 
Displaying RIP Information 
All RIP configuration and status information is shown by the CLI command 
show ip rip and options off that command. The following RIP information can 
be displayed: 
RIP Information Type  Page 
General Information 
11-28 
Interface Information 
11-30 
Peer Information 
11-31 
Redistribute Information 
11-33 
Restrict Information 
11-33 
11-27