CCNP(BSCI)实验：路由器之间的负载均衡实验

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starshomes 2020-09-27 12:05:28 ©著作权

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实验（一）R2与R3之间的负载均衡预配置 R2上的配置 R2(config)#int lo0 R2(config-if)#ip add 2.2.2.2 255.255.255.0 R2(config-if)#int s2/2 R2(config-if)#ip add 23.0.0.2 255.255.255.0 R2(config-if)#no sh R2(config-if)#int f0/0 R2(config-if)#ip add 123.0.0.2 255.255.255.0 R2(config-if)#no sh R3上的配置 R3(config)#int lo0 R3(config-if)#ip add 3.3.3.3 255.255.255.0 R3(config-if)#int s2/1 R3(config-if)#ip add 23.0.0.3 255.255.255.0 R3(config-if)#no sh R3(config-if)#int f0/0 R3(config-if)#ip add 123.0.0.3 255.255.255.0 R3(config-if)#no sh

实验过程：第一步：在R2上加两条去3.3.3.0网段的路由 R2#conf t Enter configuration commands, one per line. End with CNTL/Z. R2(config)#ip route 3.3.3.0 255.255.255.0 23.0.0.3 R2(config)#ip route 3.3.3.0 255.255.255.0 123.0.0.3 R2(config)#exit R2#sh ip rou Codes: C - connected, S - static, 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 i - IS-IS, su - IS-IS summary, 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

2.0.0.0/24 is subnetted, 1 subnets C 2.2.2.0 is directly connected, Loopback0 3.0.0.0/24 is subnetted, 1 subnets S 3.3.3.0 [1/0] via 23.0.0.3 [1/0] via 123.0.0.3 //我们在这里看到去3.3.3.0的两个 23.0.0.0/24 is subnetted, 1 subnets C 23.0.0.0 is directly connected, Serial2/2 123.0.0.0/24 is subnetted, 1 subnets C 123.0.0.0 is directly connected, FastEthernet0/0 R2# 第二步：ping3.3.3.3 R2#ping 3.3.3.3

Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 3.3.3.3, timeout is 2 seconds: !.!.! //为什么会出现这种情况，罕见的 !.!.! Success rate is 60 percent (3/5), round-trip min/avg/max = 20/60/84 ms R2# 在R2上debug ip packet后看到只有23.0.0.3接口通过的成功了 *Nov 16 21:49:44.103: IP: tableid=0, s=123.0.0.2 (local), d=3.3.3.3 (FastEthernet0/0), routed via RIB *Nov 16 21:49:44.103: IP: s=123.0.0.2 (local), d=3.3.3.3 (FastEthernet0/0), len 100, sending *Nov 16 21:49:44.107: IP: s=123.0.0.2 (local), d=3.3.3.3 (FastEthernet0/0), len 100, encapsulation failed *Nov 16 21:49:46.099: IP: tableid=0, s=23.0.0.2 (local), d=3.3.3.3 (Serial2/2), routed via RIB *Nov 16 21:49:46.099: IP: s=23.0.0.2 (local), d=3.3.3.3 (Serial2/2), len 100, sending *Nov 16 21:49:46.143: IP: tableid=0, s=3.3.3.3 (Serial2/2), d=23.0.0.2 (Serial2/2), routed via RIB *Nov 16 21:49:46.147: IP: s=3.3.3.3 (Serial2/2), d=23.0.0.2 (Serial2/2), len 100, rcvd 3 *Nov 16 21:49:46.151: IP: tableid=0, s=123.0.0.2 (local), d=3.3.3.3 (FastEthernet0/0), routed via RIB *Nov 16 21:49:46.151: IP: s=123.0.0.2 (local), d=3.3.3.3 (FastEthernet0/0), len 100, sending *Nov 16 21:49:46.155: IP: s=123.0.0.2 (local), d=3.3.3.3 (FastEthernet0/0), len 100, encapsulation failed.! *Nov 16 21:49:48.147: IP: tableid=0, s=23.0.0.2 (local), d=3.3.3.3 (Serial2/2), routed via RIB *Nov 16 21:49:48.147: IP: s=23.0.0.2 (local), d=3.3.3.3 (Serial2/2), len 100, sending *Nov 16 21:49:48.191: IP: tableid=0, s=3.3.3.3 (Serial2/2), d=23.0.0.2 (Serial2/2), routed via RIB *Nov 16 21:49:48.195: IP: s=3.3.3.3 (Serial2/2), d=23.0.0.2 (Serial2/2), len 100, rcvd 3 *Nov 16 21:49:48.199: IP: tableid=0, s=123.0.0.2 (local), d=3.3.3.3 (FastEthernet0/0), routed via RIB *Nov 16 21:49:48.203: IP: s=123.0.0.2 (local), d=3.3.3.3 (FastEthernet0/0), len 100, sending *Nov 16 21:49:48.207: IP: s=123.0.0.2 (local), d=3.3.3.3 (FastEthernet0/0), len 100, encapsulation failed Success rate is 40 percent (2/5), round-trip min/avg/max = 48/48/48 ms R2# 第三步：关闭R2上的两个接口的cef表 R2(config)#int s2/2 R2(config-if)#no ip cef R2(config)#int f0/0 R2(config-if)#no ip cef R2(config)# 第四步：再Ping 3.3.3.3 （连续ping 2 次） R2#ping 3.3.3.3

Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 3.3.3.3, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 4/30/52 ms R2#sh ip route 3.3.3.3 Routing entry for 3.3.3.0/24 Known via "static", distance 1, metric 0 Routing Descriptor Blocks: 23.0.0.3 Route metric is 0, traffic share count is 1

123.0.0.3 （走下面一条） Route metric is 0, traffic share count is 1

R2#ping 3.3.3.3

Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 3.3.3.3, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 8/30/60 ms R2#sh ip route 3.3.3.3 Routing entry for 3.3.3.0/24 Known via "static", distance 1, metric 0 Routing Descriptor Blocks:

23.0.0.3 （走上面一条） Route metric is 0, traffic share count is 1 123.0.0.3 Route metric is 0, traffic share count is 1

R2# 实验（二）当R2为穿越流量时的实验实验过程：第一步：在R1上ping3.3.3.3 R1#ping 3.3.3.3

Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 3.3.3.3, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 8/46/96 ms R1# R1# R1# 第二步：查看是否在R2上负载均衡 R1#traceroute 3.3.3.3

Type escape sequence to abort. Tracing the route to 3.3.3.3

1 12.0.0.2 28 msec 48 msec 24 msec 2 23.0.0.3 8 msec * 24 msec R1#traceroute 3.3.3.3

Type escape sequence to abort. Tracing the route to 3.3.3.3

1 12.0.0.2 60 msec 28 msec 12 msec 2 123.0.0.3 32 msec * 28 msec //只有一条？？ R1# 第三步：关闭R2上与R3相连的两个接口的route-cache表 R2(config)#int s2/2 R2(config-if)#no ip route R2(config-if)#no ip route-c R2(config-if)#int f0/0 R2(config-if)#no ip route-c R2(config-if)#

第四步：跟踪R1 ping 3.3.3.3 的过程 R1#traceroute 3.3.3.3

Type escape sequence to abort. Tracing the route to 3.3.3.3

1 12.0.0.2 64 msec 12 msec 96 msec 2 123.0.0.3 36 msec 23.0.0.3 24 msec * （over--success） R1# 第五步：取消第三步并查看结果 R1#traceroute 3.3.3.3

Type escape sequence to abort. Tracing the route to 3.3.3.3

1 12.0.0.2 52 msec 56 msec 12 msec 2 123.0.0.3 40 msec * 32 msec R1#