debug ip rip clear ip route *

R1#debug ip rip
RIP protocol debugging is on
R1#clear ip rout
R1#clear ip route *
R1#
R1#RIP: sending  v1 update to 255.255.255.255 via FastEthernet0/0 (172.31.0.1)
RIP: build update entries
      network 172.31.1.0 metric 1
      network 172.31.12.0 metric 1
RIP: sending  v1 update to 255.255.255.255 via FastEthernet0/1 (172.31.1.1)
RIP: build update entries
      network 172.31.0.0 metric 1
      network 172.31.12.0 metric 1
RIP: sending  v1 update to 255.255.255.255 via Serial1/0 (172.31.12.1)
RIP: build update entries
      network 172.31.0.0 metric 1
      network 172.31.1.0 metric 1
RIP: received v1 update from 172.31.12.2 on Serial1/0
      172.31.2.0 in 1 hops

clear ip route *  //清空路由表