CCNP实验---Eigrp Stub 区域

拓扑：

 

RA:ip route
     1.0.0.0/24 is subnetted, 1 subnets
C       1.1.1.0 is directly connected, Loopback0
     2.0.0.0/24 is subnetted, 1 subnets
D       2.2.2.0 [90/2297856] via 12.1.1.2, 00:01:26, Serial2/1
     3.0.0.0/24 is subnetted, 1 subnets
D       3.3.3.0 [90/2809856] via 12.1.1.2, 00:00:37, Serial2/1
     23.0.0.0/30 is subnetted, 1 subnets
D       23.1.1.0 [90/2681856] via 12.1.1.2, 00:01:26, Serial2/1
     12.0.0.0/30 is subnetted, 1 subnets
C       12.1.1.0 is directly connected, Serial2/1

 

RB:ip route
     1.0.0.0/24 is subnetted, 1 subnets
D       1.1.1.0 [90/2297856] via 12.1.1.1, 00:02:30, Serial2/1
     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
D       3.3.3.0 [90/2297856] via 23.1.1.1, 00:01:41, Serial2/2
     23.0.0.0/30 is subnetted, 1 subnets
C       23.1.1.0 is directly connected, Serial2/2
     12.0.0.0/30 is subnetted, 1 subnets
C       12.1.1.0 is directly connected, Serial2/1

 

RC:ip route
     1.0.0.0/24 is subnetted, 1 subnets
D       1.1.1.0 [90/2809856] via 23.1.1.2, 00:02:06, Serial2/2
     2.0.0.0/24 is subnetted, 1 subnets
D       2.2.2.0 [90/2297856] via 23.1.1.2, 00:02:06, Serial2/2
     3.0.0.0/24 is subnetted, 1 subnets
C       3.3.3.0 is directly connected, Loopback0
     23.0.0.0/30 is subnetted, 1 subnets
C       23.1.1.0 is directly connected, Serial2/2
     12.0.0.0/30 is subnetted, 1 subnets
D       12.1.1.0 [90/2681856] via 23.1.1.2, 00:02:06, Serial2/2

 

说明网络正常收敛，现在没有设置stub，把RB上的环回口关掉，用debug来查看RB查询：
RB#debug eigrp packets query
EIGRP Packets debugging is on
    (QUERY)
RB#
RB#conf ter
Enter configuration commands, one per line.  End with CNTL/Z.
RB(config)#
RB(config)#int loopback 0
RB(config-if)#shu
*Mar  1 00:11:38.587: EIGRP: Enqueueing QUERY on Serial2/1 iidbQ un/rely 0/1 serno 6-6
*Mar  1 00:11:38.591: EIGRP: Enqueueing QUERY on Serial2/1 nbr 12.1.1.1 iidbQ un/rely 0/0 peerQ un/rely 0/0 serno 6-6
*Mar  1 00:11:38.599: EIGRP: Sending QUERY on Serial2/1 nbr 12.1.1.1  //向RA发送查询
*Mar  1 00:11:38.603:   AS 10, Flags 0x0, Seq 10/3 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/1 serno 6-6
*Mar  1 00:11:38.607: EIGRP: Enqueueing QUERY on Serial2/2 iidbQ un/rely 0/1 serno 6-6
*Mar  1 00:11:38.611: EIGRP: Enqueueing QUERY on Serial2/2 nbr 23.1.1.1 iidbQ un/rely 0/0 peerQ un/rely 0/0 serno 6-6
*Mar  1 00:11:38.619: EIGRP: Sending QUERY on Serial2/2 nbr 23.1.1.1  //向RB发送查查询
*Mar  1 00:11:38.623:   AS 10, Flags 0x0, Seq 11/3 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/1 serno 6-6

把RB上的loopback 0 打开，让网络回到正常的收敛
当把RC设置成STUB区域时
RC(config)#router ei 100
RC(config-router)#eigrp stub receive-only

此时关掉RB上的loopback 0
再来看RB的查询情况：

*Mar  1 00:18:13.139: EIGRP: Enqueueing QUERY on Serial2/2 iidbQ un/rely 0/1 serno 9-9
*Mar  1 00:18:13.143: EIGRP: Enqueueing QUERY on Serial2/2 nbr 23.1.1.1 iidbQ un/rely 0/0 peerQ un/rely 0/0 serno 9-9
*Mar  1 00:18:13.151: EIGRP: Enqueueing QUERY on Serial2/1 iidbQ un/rely 0/1 serno 9-9
*Mar  1 00:18:13.155: EIGRP: Enqueueing QUERY on Serial2/1 nbr 12.1.1.1 iidbQ un/rely 0/0 peerQ un/rely 0/0 serno 9-9
*Mar  1 00:18:13.163: EIGRP: Sending QUERY on Serial2/1 nbr 12.1.1.1 //向RA发送查询
*Mar  1 00:18:13.163:   AS 10, Flags 0x0, Seq 19/8 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/1 serno 9-9
*Mar  1 00:18:13.351: EIGRP: Received QUERY on Serial2/2 nbr 23.1.1.1
RB(config-if)#
*Mar  1 00:18:13.355:   AS 10, Flags 0x0, Seq 11/21 idbQ 0/0 iidbQ un/rely 0/0 peerQ un/rely 0/0

始终没有发现向RC发送查询。

 

总结：
SIA(陷入主动状态)的过程：
1. RB丢失路由.
2. 查EIGRP TOPOLOGY, 查看有没有FS,如有.直接放入路由表
3. 如没有,则发QUERY报文给所有的邻居
4. 有一方不回应.最大的容忍时间:是SIA定时器所定议的时间,超时.关闭此邻接关系.
5. 重新发送更新.重新计算.

解决SIA的办法
把边界路由器打成STUB区域

EIGRP STUB
在路由协议的边界.用于控制哪些路由可以发送出去.特别用于不需了解太多路由的网络,
? Eigrp stub receive-only ---只接收.不发送任何路由,注意与DENY ANY 的区别!
? Eigrp stub static      ---只发送STATIC路由, 注意STATIC路由应再分布进入EIGRP 即：R1(config-router)#net 192.168.78.0 (这是静态路由的目的地址。R1(config)#ip route 192.168.78.1.0    255.255.255.0   f0/0）
? Eigrp stub connected  ---只发送直连接口所在的网段, 注意此接口应运行EIGRP
? Eigrp stub summary  ---此汇总路由应在EIGRP数据库中.且是汇总到有类边界,接口汇总路由也可以发送
? Eigrp stub           ---默认等同于eigrp stub connect summary
注: Show ip eigrp neighbor detail 可以看到自己的邻居是否是一个stub路由器，并且可以看到stub路由器的发送机制到底是什么。
除了receive-only以外，其他的参数可自由组合