CCNP路由实验---6、理解EIGRP的查询

实验目的：

1、理解EIGRP的路由更新机制。

2、掌握EIGRP的调试命令。

3、掌握stub的配置及使用路由汇总限制EIGRP的查询范围。

实验拓扑：

 

实验步骤：

1、配置各路由器的名称、相连接口IP地址，并且使用Ping命令确认各路由器的直连口的互通性。

R1配置：

R1(config)#int fa0/0

R1(config-if)#ip add 192.138.1.1 255.255.255.0

R1(config-if)#no shut

R1(config-if)#exit

R1(config)#int s1/2

R1(config-if)#ip add 172.16.1.1 255.255.255.252

R1(config-if)#no shut

R1(config-if)#exit

R1(config)#int loop 1

R1(config-if)#ip add 10.1.1.1 255.255.255.0

R1(config-if)#exit

   R2、R3类似。

2、给三台路由器配置EGIRP协议，自治系统号为80。本次实验采用通配符掩码配置R1的回环口。

R1(config)#router eigrp 80

R1(config-router)#network 172.16.0.0

R1(config-router)#network 192.138.0.0

R1(config-router)#network 10.1.0.0 0.0.255.255

R2、R3同理配置好。

3、查看R1、R2与R3的路由表，确认EIGRP工作正常。

R1：

R1#sh ip route

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

 

     172.16.0.0/16 is variably subnetted, 3 subnets, 2 masks

D       172.16.1.4/30 [90/2681856] via 172.16.1.2, 00:01:48, Serial1/2

D       172.16.0.0/16 is a summary, 00:02:48, Null0

C       172.16.1.0/30 is directly connected, Serial1/2

     10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks

C       10.1.1.0/24 is directly connected, Loopback1

D       10.0.0.0/8 is a summary, 00:02:48, Null0

C    192.138.1.0/24 is directly connected, FastEthernet0/0

R2：

R2#sh ip route eigrp

D    10.0.0.0/8 [90/2297856] via 172.16.1.1, 00:08:27, Serial1/0R3：

R3#sh ip route eigrp

     172.16.0.0/30 is subnetted, 2 subnets

D       172.16.1.0 [90/2681856] via 172.16.1.5, 00:03:17, Serial1/2

D    10.0.0.0/8 [90/2809856] via 172.16.1.5, 00:03:17, Serial1/2

4、在R2路由器上使用debug命令跟踪EIGRP的更新。

R2#debug eigrp fsm

EIGRP FSM Events/Actions debugging is on

R2#debug eigrp packets query

EIGRP Packets debugging is on

(QUERY)

===debug eigrp fsm ：这条调试命令显示关于EIGRPfeasible successor度量值（FSM）的信息。
===debug eigrp packet ：这条调试命令显示在路由器间的任意EIGRP报文行进的信息。

5、在R1路由器上使用shutdown命令，重激活loopback的接口，模拟网络出错。

R1#conf t

Enter configuration commands, one per line.  End with CNTL/Z.

R1(config)#int loop 1

R1(config-if)#shutdown

R1(config-if)#

*Oct 18 22:45:10.883: %LINK-5-CHANGED: Interface Loopback1, changed state to administratively down
此刻观察R2的输出结果：

R2#

*Oct 18 22:45:08.635: EIGRP: Received QUERY on Serial1/0 nbr 172.16.1.1

*Oct 18 22:45:08.639:   AS 80, Flags 0x0, Seq 3/2 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/0

*Oct 18 22:45:08.643: DUAL: dest(10.1.1.0/24) not active

*Oct 18 22:45:08.643: DUAL: rcvquery: 10.1.1.0/24 via 172.16.1.1 metric 4294967295/4294967295, RD is 4294967295

*Oct 18 22:45:08.647: DUAL: send REPLY(r1/n1) about 10.1.1.0/24 to 172.16.1.1

*Oct 18 22:45:08.647: DUAL: dest(172.16.0.0/16) not active

*Oct 18 22:45:08.651: DUAL: rcvquery: 172.16.0.0/16 via 172.16.1.1 metric 4294967295/4294967295, RD is 4294967295

*Oct 18 22:45:08.655: DUAL: send REPLY(r1/n1) about 172.16.0.0/16 to 172.16.1.1

*Oct 18 22:45:08.655: DUAL: rcvquery: 10.0.0.0/8 via 172.16.1.1 metric 4294967295/4294967295, RD is 2297856

*Oct 18 22:45:08.659: DUAL: Find FS for dest 10.0.0.0/8. FD is 2297856, RD is 2297856

*Oct 18 22:45:08.659: DUAL:     172.16.1.1 metric 4294967295/4294967295 not found Dmin is 4294967295

*Oct 18 22:45:08.663: DUAL: Peer total/stub 2/0 template/full-stub 2/0

*Oct 18 22:45:08.663: DUAL: Dest 10.0.0.0/8 entering active state.

*Oct 18 22:45:08.663: DUAL: Set reply-status table. Count is 2.

*Oct 18 22:45:08.663: DUAL: Not doing split horizon

*Oct 18 22:45:08.663: DUAL: Going from state 1 to state 3

*Oct 18 22:45:08.675: EIGRP: Enqueueing QUERY on Serial1/1 iidbQ un/rely 0/1 serno 6-6

*Oct 18 22:45:08.679: EIGRP: Enqueueing QUERY on Serial1/1 nbr 172.16.1.6 iidbQ un/rely 0/0 peerQ un/rely 0/0 serno 6-6

*Oct 18 22:45:08.683: EIGRP: Sending QUERY on Serial1/1 nbr 172.16.1.6

*Oct 18 22:45:08.687:   AS 80, Flags 0x0, Seq 5/2 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/1 serno 6-6

*Oct 18 22:45:08.703: DUAL: Removing dest 10.1.1.0/24, nexthop 172.16.1.1

*Oct 18 22:45:08.703: DUAL: No routes.  Flushing dest 10.1.1.0/24

*Oct 18 22:45:08.703: DUAL: Removing dest 172.16.0.0/16, nexthop 172.16.1.1

*Oct 18 22:45:08.703: DUAL: No routes.  Flushing dest 172.16.0.0/16

*Oct 18 22:45:08.703: EIGRP: Enqueueing QUERY on Serial1/0 iidbQ un/rely 0/1 serno 6-6

*Oct 18 22:45:08.707: EIGRP: Enqueueing QUERY on Serial1/0 nbr 172.16.1.1 iidbQ un/rely 0/0 peerQ un/rely 0/0 serno 6-6

*Oct 18 22:45:08.711: EIGRP: Sending QUERY on Serial1/0 nbr 172.16.1.1

*Oct 18 22:45:08.715:   AS 80, Flags 0x0, Seq 6/3 idbQ 1/0 iidbQ un/rely 0/0 peerQ un/rely 0/1 serno 6-6

*Oct 18 22:45:08.739: DUAL: dest(10.0.0.0/8) active

*Oct 18 22:45:08.739: DUAL: rcvreply: 10.0.0.0/8 via 172.16.1.6 metric 4294967295/4294967295

*Oct 18 22:45:08.739: DUAL: reply count is 2

*Oct 18 22:45:08.739: DUAL: Clearing handle 1, count now 1

*Oct 18 22:45:08.739: DUAL: Removing dest 10.0.0.0/8, nexthop 172.16.1.6

*Oct 18 22:45:08.779: DUAL: rcvreply: 10.0.0.0/8 via 172.16.1.1 metric 4294967295/4294967295

*Oct 18 22:45:08.779: DUAL: reply count is 1

*Oct 18 22:45:08.779: DUAL: Clearing handle 0, count now 0

*Oct 18 22:45:08.783: DUAL: Freeing reply status table

*Oct 18 22:45:08.783: DUAL: Find FS for dest 10.0.0.0/8. FD is 4294967295, RD is 4294967295 found

*Oct 18 22:45:08.787: DUAL: send REPLY(r1/n1) about 10.0.0.0/8 to 172.16.1.1

*Oct 18 22:45:08.787: DUAL: Going from state 3 to state 1

*Oct 18 22:45:08.843: DUAL: Removing dest 10.0.0.0/8, nexthop 172.16.1.1

*Oct 18 22:45:08.843: DUAL: No routes.  Flushing dest 10.0.0.0/8

根据提示，可以发现共有4查询包，与之相对应的会产生4个回复包。如果在实际应用中，使用EIGRP的网络可以多达数十台及数百台路由，那么如果出现某个网络出错，则有可以引起整个网络产生大量的查询回复包。所以为了避免这样的问题，可以使用ip summary命令或stub参数来进行配置EIGRP，限制EIGRP的查询范围。

6、在R1、R3上进行路由汇总

R1：

R1(config)#int loop 1

R1(config-if)#no shut

R1(config-if)#exit

R1(config)#int s1/2

R1(config-if)#ip summary-address eigrp 80 10.0.0.0 255.0.0.0

 

R3：

R3(config)#int s1/2

R3(config-if)#ip summary-address eigrp 80 10.0.0.0 255.0.0.0

7、观察R2、R3的路由表，确认已经学习到 10.1.1 .0/24的网络汇总路由。

R2：

R2#sh ip route eigrp

D    10.0.0.0/8 [90/2297856] via 172.16.1.1, 00:00:46, Serial1/0

R3：

R2#  ping 10.1.1.1

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 10.1.1.1, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 4/17/40 ms

 

R3：

R3#sh ip route eigrp

     172.16.0.0/30 is subnetted, 2 subnets

D       172.16.1.0 [90/2681856] via 172.16.1.5, 00:08:23, Serial1/2

D    10.0.0.0/8 [90/2809856] via 172.16.1.5, 00:08:23, Serial1/2

R3#ping 10.1.1.1

 

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 10.1.1.1, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 24/40/48 ms

8、在R1路由器上，再次shutdown掉loopback0接口，同时观察R2的debug信息。

R2#

*Oct 18 23:01:28.843: EIGRP: Received QUERY on Serial1/0 nbr 172.16.1.1              ①

*Oct 18 23:01:28.847:   AS 80, Flags 0x0, Seq 8/12 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/0

*Oct 18 23:01:28.851: DUAL: dest(10.1.1.0/24) not active

*Oct 18 23:01:28.851: DUAL: rcvquery: 10.1.1.0/24 via 172.16.1.1 metric 4294967295/4294967295, RD is 4294967295

*Oct 18 23:01:28.855: DUAL: send REPLY(r1/n1) about 10.1.1.0/24 to 172.16.1.1

*Oct 18 23:01:28.855: DUAL: dest(172.16.0.0/16) not active

*Oct 18 23:01:28.859: DUAL: rcvquery: 172.16.0.0/16 via 172.16.1.1 metric 4294967295/4294967295, RD is 4294967295

*Oct 18 23:01:28.859: DUAL: send REPLY(r1/n1) about 172.16.0.0/16 to 172.16.1.1       I

*Oct 18 23:01:28.863: DUAL: rcvquery: 10.0.0.0/8 via 172.16.1.1 metric 4294967295/4294967295, RD is 2297856

*Oct 18 23:01:28.867: DUAL: Find FS for dest 10.0.0.0/8. FD is 2297856, RD is 2297856

*Oct 18 23:01:28.867: DUAL:     172.16.1.1 metric 4294967295/4294967295 not found Dmin is 4294967295

*Oct 18 23:01:28.867: DUAL: Peer total/stub 2/0 template/full-stub 2/0

*Oct 18 23:01:28.867: DUAL: Dest 10.0.0.0/8 entering active state.

*Oct 18 23:01:28.867: DUAL: Set reply-status table. Count is 2.

*Oct 18 23:01:28.867: DUAL: Not doing split horizon

*Oct 18 23:01:28.867: DUAL: Going from state 1 to state 3

*Oct 18 23:01:28.879: EIGRP: Enqueueing QUERY on Serial1/1 iidbQ un/rely 0/1 serno 13-13

*Oct 18 23:01:28.883: EIGRP: Enqueueing QUERY on Serial1/1 nbr 172.16.1.6 iidbQ un/rely 0/0 peerQ un/rely 0/0 serno 13-13

*Oct 18 23:01:28.887: EIGRP: Sending QUERY on Serial1/1 nbr 172.16.1.6              ②

*Oct 18 23:01:28.891:   AS 80, Flags 0x0, Seq 16/8 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/1 serno 13-13

*Oct 18 23:01:28.915: DUAL: Removing dest 10.1.1.0/24, nexthop 172.16.1.1

*Oct 18 23:01:28.915: DUAL: No routes.  Flushing dest 10.1.1.0/24

*Oct 18 23:01:28.915: DUAL: Removing dest 172.16.0.0/16, nexthop 172.16.1.1

*Oct 18 23:01:28.915: DUAL: No routes.  Flushing dest 172.16.0.0/16

*Oct 18 23:01:28.915: EIGRP: Enqueueing QUERY on Serial1/0 iidbQ un/rely 0/1 serno 13-13

*Oct 18 23:01:28.919: EIGRP: Enqueueing QUERY on Serial1/0 nbr 172.16.1.1 iidbQ un/rely 0/0 peerQ un/rely 0/0 serno 13-13

*Oct 18 23:01:28.923: EIGRP: Sending QUERY on Serial1/0 nbr 172.16.1.1             II

*Oct 18 23:01:28.927:   AS 80, Flags 0x0, Seq 17/8 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/1 serno 13-13

*Oct 18 23:01:28.931: DUAL: dest(10.0.0.0/8) active

*Oct 18 23:01:28.935: DUAL: rcvreply: 10.0.0.0/8 via 172.16.1.6 metric 4294967295/4294967295

*Oct 18 23:01:28.935: DUAL: reply count is 2

*Oct 18 23:01:28.935: DUAL: Clearing handle 1, count now 1

*Oct 18 23:01:28.939: DUAL: Removing dest 10.0.0.0/8, nexthop 172.16.1.6

*Oct 18 23:01:28.991: DUAL: rcvreply: 10.0.0.0/8 via 172.16.1.1 metric 4294967295/4294967295

*Oct 18 23:01:28.991: DUAL: reply count is 1

*Oct 18 23:01:28.991: DUAL: Clearing handle 0, count now 0

*Oct 18 23:01:28.991: DUAL: Freeing reply status table

*Oct 18 23:01:28.991: DUAL: Find FS for dest 10.0.0.0/8. FD is 4294967295, RD is 4294967295 found

*Oct 18 23:01:28.991: DUAL: send REPLY(r1/n1) about 10.0.0.0/8 to 172.16.1.1         III

*Oct 18 23:01:28.991: DUAL: Going from state 3 to state 1

*Oct 18 23:01:29.063: DUAL: Removing dest 10.0.0.0/8, nexthop 172.16.1.1

*Oct 18 23:01:29.063: DUAL: No routes.  Flushing dest 10.0.0.0/8

通过配置汇总，我们可以发现，本次查询中只有2次关于 10.1.1 .0/24的网络查询。如日志里面的阴暗部分，为了方便查寻我用圆圈标示了第一、二次。另外3个查询是由于配置了汇总后。R1和R3查询10.0.0.0/8的网络而产生的，用粗体表示，并用罗马字体标示了顺序。

9、为了能够彻底解决查询的问题。我们在R2上配置EIGRP stub的特性。以阻止向路由器R2查询 10.0.0 .0/8的网络路由:

R2#conf t

Enter configuration commands, one per line.  End with CNTL/Z.

R2(config)#router eigrp 80

R2(config-router)#eigrp stub       //配置R2为末节属性。

在R1或R3上查看邻居表，观察末节特性。

R1#sh ip eigrp nei detail

IP-EIGRP neighbors for process 80

H   Address                 Interface       Hold Uptime   SRTT   RTO  Q  Seq

                                            (sec)         (ms)       Cnt Num

0   172.16.1.2              Se1/2             12 00:00:43  631  3786  0  19

   Version 12.3/1.2, Retrans: 0, Retries: 0

   Stub Peer Advertising ( CONNECTED SUMMARY ) Routes   // EIGRP不会向被配置了末节特性的路由器查询其它网络的路由。

   Suppressing queries

10、最后我们再来一次对R1的loopback 端口关闭、激活一次，观察R2路由器的提示信息：

R2(config-router)#

*Oct 18 23:09:04.675: DUAL: rcvupdate: 10.0.0.0/8 via 172.16.1.1 metric 4294967295/4294967295

*Oct 18 23:09:04.675: DUAL: Find FS for dest 10.0.0.0/8. FD is 2297856, RD is 2297856

*Oct 18 23:09:04.679: DUAL:     172.16.1.1 metric 4294967295/4294967295 not found Dmin is 4294967295

*Oct 18 23:09:04.679: DUAL: Peer total/stub 2/0 template/full-stub 2/0

*Oct 18 23:09:04.679: DUAL: Dest 10.0.0.0/8 entering active state.

*Oct 18 23:09:04.679: DUAL: Set reply-status table. Count is 2.

*Oct 18 23:09:04.679: DUAL: Not doing split horizon

*Oct 18 23:09:04.691: EIGRP: Enqueueing QUERY on Serial1/0 iidbQ un/rely 0/1 serno 16-16

*Oct 18 23:09:04.695: EIGRP: Enqueueing QUERY on Serial1/1 iidbQ un/rely 0/1 serno 16-16

*Oct 18 23:09:04.695: EIGRP: Enqueueing QUERY on Serial1/0 nbr 172.16.1.1 iidbQ un/rely 0/0 peerQ un/rely 0/0 serno 16-16

*Oct 18 23:09:04.699: EIGRP: Enqueueing QUERY on Serial1/1 nbr 172.16.1.6 iidbQ un/rely 0/0 peerQ un/rely 0/0 serno 16-16

*Oct 18 23:09:04.703: EIGRP: Sending QUERY on Serial1/0 nbr 172.16.1.1 //向R1查询

*Oct 18 23:09:04.707:   AS 80, Flags 0x0, Seq 23/13 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/1 serno 16-16

*Oct 18 23:09:04.711: EIGRP: Sending QUERY on Serial1/1 nbr 172.16.1.6//向R3查询

*Oct 18 23:09:04.711:   AS 80, Flags 0x0, Seq 24/11 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/1 serno 16-16

*Oct 18 23:09:04.755: DUAL: rcvreply: 10.0.0.0/8 via 172.16.1.1 metric 4294967295/4294967295

*Oct 18 23:09:04.755: DUAL: reply count is 2

*Oct 18 23:09:04.755: DUAL: Clearing handle 0, count now 1

*Oct 18 23:09:04.763: DUAL: dest(10.0.0.0/8) active

*Oct 18 23:09:04.763: DUAL: rcvreply: 10.0.0.0/8 via 172.16.1.6 metric 4294967295/4294967295

*Oct 18 23:09:04.763: DUAL: reply count is 1

*Oct 18 23:09:04.763: DUAL: Clearing handle 1, count now 0

*Oct 18 23:09:04.763: DUAL: Freeing reply status table

*Oct 18 23:09:04.763: DUAL: Find FS for dest 10.0.0.0/8. FD is 4294967295, RD is 4294967295 found

*Oct 18 23:09:04.763: DUAL: Removing dest 10.0.0.0/8, nexthop 172.16.1.1

*Oct 18 23:09:04.763: DUAL: Removing dest 10.0.0.0/8, nexthop 172.16.1.6

*Oct 18 23:09:04.763: DUAL: No routes.  Flushing dest 10.0.0.0/8

经过如上配置后，可以发现R2不再接收到关于 10.1.1 .0/24的网络的查询包。仅仅有关于10.0.0.0/8网络的本地查询包被发出。因此使用汇总和stub可以有效的避免路由出现SIA状态，同时解决了EIGRP的路由收敛问题,以保证EIGRP的收敛变得简单可行。

至此，实验完成。

 

本文转自 独钩寒江雪 51CTO博客，原文链接：http://blog.51cto.com/bennie/407846，如需转载请自行联系原作者