实验说明：通过使用debug命令基于每个分组和每个目的地来考察等开销负载均衡。

　　实验配置：

r1#sh run
interface Ethernet0
 ip address 10.0.0.1 255.255.255.0
!
interface Serial0
 ip address 192.168.1.2 255.255.255.0
!
router rip
 network 10.0.0.0
 network 192.168.1.0
!

r2#sh run
interface Loopback0
 ip address 192.168.3.2 255.255.255.0 secondary
 ip address 192.168.3.1 255.255.255.0
!
interface Serial0
 ip address 192.168.1.1 255.255.255.0
 clockrate 64000
!
interface Serial1
 ip address 192.168.2.1 255.255.255.0
 clockrate 64000
!
router rip
 network 192.168.1.0
 network 192.168.2.0
 network 192.168.3.0
!

r3#sh run
interface Ethernet0
 ip address 10.0.0.2 255.255.255.0
!
interface Serial1
 ip address 192.168.2.2 255.255.255.0
!
router rip
 network 10.0.0.0
 network 192.168.2.0
!

r2#sh ip route
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
       i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area
       * - candidate default, U - per-user static route, o - ODR
       P - periodic downloaded static route
Gateway of last resort is not set
R    10.0.0.0/8 [120/1] via 192.168.1.2, 00:00:23, Serial0
                        [120/1] via 192.168.2.2, 00:00:19, Serial1
C    192.168.1.0/24 is directly connected, Serial0
C    192.168.2.0/24 is directly connected, Serial1
C    192.168.3.0/24 is directly connected, Loopback0