CCNP-18 IS-IS试验1
试验拓扑：
试验要求：R1 R2为区域49.0001中的IS，R3为区域49.0002中的IS，并且把R1只配之成为Level-1路由器，R3为Level-2路由器，R1与R2之间的链路配置成为L1链路，R2与R3之间的链路配置成为L2链路。
试验目的：掌握ISIS基本的配置方法。
实验配置：
R1：
R1(config)#clns routing
R1(config)#router isis
R1(config-router)#net 49.0001.1111.1111.1111.00
R1(config-router)#is-type level-1
R1(config-router)#exit
R1(config)#int f0/0
R1(config-if)#clns router isis
R1(config-if)#isis circuit-type level-1
R1(config-if)#no shu
R1(config-if)#exit
R2：
R2(config)#clns routing
R2(config)#router isis
R2(config-router)#net 49.0001.2222.2222.2222.00
R2(config-router)#exit
R2(config)#int f0/0
R2(config-if)#clns router isis
R2(config-if)#isis circuit-type level-1
R2(config-if)#no shu
R2(config-if)#exit
R2(config)#int s1/0
R2(config-if)#clns router isis
R2(config-if)#clock rate 64000
R2(config-if)#no shu
R2(config-if)#isis circuit-type level-2-only
R2(config-if)#end
R3：
R3(config)#clns routing
R3(config)#router isis
R3(config-router)#net 49.0002.3333.3333.3333.00
R3(config-router)#is-type level-2-only
R3(config-router)#exit
R3(config)#int s1/0
R3(config-if)#clns router isis
R3(config-if)#isis circuit-type level-2-only
R3(config-if)#no shu
R3(config-if)#exit
以上为ISIS的基本配置，ISIS路由器默认为level-1-2，可以通过路由器配置模式下命令is-type来进行修改，接口的ISIS类型默认也为level-1-2，同样可以通过接口配置模式下命令isis circuit-type进行修改。下面我们在每台路由器上show clns neighbors查看clns邻居关系：
R1#show clns neighbors
System Id Interface SNPA State Holdtime Type Protocol
R2 Fa0/0 ca00.07b8.0000 Up 18 L1 IS-IS
R2#show clns neighbors
System Id Interface SNPA State Holdtime Type Protocol
R1 Fa0/0 ca00.06a4.0000 Up 26 L1 IS-IS
R3 Se1/0 *HDLC* Up 21 L2 IS-IS
R3#show clns neighbors
System Id Interface SNPA State Holdtime Type Protocol
R2 Se1/0 *HDLC* Up 25 L2 IS-IS
OK，都成功建立了邻居关系，需要注意的是SNPA的区别，在LAN环境下为LAN接口的MAC地址，WAN环境下为DLCI或者HDLC。
Show clns interface命令查看接口的CLNS运行情况：
R1#show clns interface
FastEthernet0/0 is up, line protocol is up
Checksums enabled, MTU 1497, Encapsulation SAP
ERPDUs enabled, min. interval 10 msec.
RDPDUs enabled, min. interval 100 msec., Addr Mask enabled
Congestion Experienced bit set at 4 packets
CLNS fast switching enabled
CLNS SSE switching disabled
DEC compatibility mode OFF for this interface
Next ESH/ISH in 23 seconds
Routing Protocol: IS-IS
Circuit Type: level-1
Interface number 0x0, local circuit ID 0x1
Level-1 Metric: 10, Priority: 64, Circuit ID: R2.01
Level-1 IPv6 Metric: 10
Number of active level-1 adjacencies: 1
Next IS-IS LAN Level-1 Hello in 3 seconds
R2#show clns interface
FastEthernet0/0 is up, line protocol is up
Checksums enabled, MTU 1497, Encapsulation SAP
ERPDUs enabled, min. interval 10 msec.
RDPDUs enabled, min. interval 100 msec., Addr Mask enabled
Congestion Experienced bit set at 4 packets
CLNS fast switching enabled
CLNS SSE switching disabled
DEC compatibility mode OFF for this interface
Next ESH/ISH in 5 seconds
Routing Protocol: IS-IS
Circuit Type: level-1
Interface number 0x0, local circuit ID 0x1
Level-1 Metric: 10, Priority: 64, Circuit ID: R2.01
Level-1 IPv6 Metric: 10
Number of active level-1 adjacencies: 1
Next IS-IS LAN Level-1 Hello in 3 seconds
Serial1/0 is up, line protocol is up
Checksums enabled, MTU 1500, Encapsulation HDLC
ERPDUs enabled, min. interval 10 msec.
RDPDUs enabled, min. interval 100 msec., Addr Mask enabled
Congestion Experienced bit set at 4 packets
CLNS fast switching enabled
CLNS SSE switching disabled
DEC compatibility mode OFF for this interface
Next ESH/ISH in 6 seconds
Routing Protocol: IS-IS
Circuit Type: level-2
Interface number 0x1, local circuit ID 0x100
Neighbor System-ID: R3
Level-2 Metric: 10, Priority: 64, Circuit ID: R2.00
Level-2 IPv6 Metric: 10
Number of active level-2 adjacencies: 1
Next IS-IS Hello in 6 seconds
if state UP
R3#show clns interface
FastEthernet0/0 is administratively down, line protocol is down
CLNS protocol processing disabled
Serial1/0 is up, line protocol is up
Checksums enabled, MTU 1500, Encapsulation HDLC
ERPDUs enabled, min. interval 10 msec.
RDPDUs enabled, min. interval 100 msec., Addr Mask enabled
Congestion Experienced bit set at 4 packets
CLNS fast switching enabled
CLNS SSE switching disabled
DEC compatibility mode OFF for this interface
Next ESH/ISH in 13 seconds
Routing Protocol: IS-IS
Circuit Type: level-2
Interface number 0x0, local circuit ID 0x100
Neighbor System-ID: R2
Level-2 Metric: 10, Priority: 64, Circuit ID: R3.00
Level-2 IPv6 Metric: 10
Number of active level-2 adjacencies: 1
Next IS-IS Hello in 4 seconds
if state UP
我们从上面的输出可以知道接口的CLNS和ISIS的信息，比如链路类型，邻居system-id，度量值等等。
再用show isis database查看每台路由器的LSDB：
R1#show isis database
IS-IS Level-1 Link State Database:
LSPID LSP Seq Num LSP Checksum LSP Holdtime ATT/P/OL
R1.00-00 * 0x00000004 0x9046 1163 0/0/0
R2.00-00 0x00000003 0x39CE 1161 0/0/0
R2.01-00 0x00000001 0x2630 1162 0/0/0
R2#show isis database
IS-IS Level-1 Link State Database:
LSPID LSP Seq Num LSP Checksum LSP Holdtime ATT/P/OL
R1.00-00 0x00000004 0x9046 1150 0/0/0
R2.00-00 * 0x00000004 0x3FBF 1192 1/0/0
R2.01-00 * 0x00000001 0x2630 1153 0/0/0
IS-IS Level-2 Link State Database:
LSPID LSP Seq Num LSP Checksum LSP Holdtime ATT/P/OL
R2.00-00 * 0x00000002 0x9767 1187 0/0/0
R3.00-00 0x00000002 0xDC20 1186 0/0/0
R3#show isis database
IS-IS Level-2 Link State Database:
LSPID LSP Seq Num LSP Checksum LSP Holdtime ATT/P/OL
R2.00-00 0x00000002 0x9767 1185 0/0/0
R3.00-00 * 0x00000002 0xDC20 1186 0/0/0
注意用红颜色标记的部分，表示R2为伪节点。
最后我们查看clns路由表：
R1#show clns route
Codes: C - connected, S - static, d - DecnetIV
I - ISO-IGRP, i - IS-IS, e - ES-IS
B - BGP, b - eBGP-neighbor
C 49.0001.1111.1111.1111.00 [1/0], Local IS-IS NET
C 49.0001 [2/0], Local IS-IS Area
R2#show clns route
Codes: C - connected, S - static, d - DecnetIV
I - ISO-IGRP, i - IS-IS, e - ES-IS
B - BGP, b - eBGP-neighbor
C 49.0001.2222.2222.2222.00 [1/0], Local IS-IS NET
C 49.0001 [2/0], Local IS-IS Area
i 49.0002 [110/10]
via R3, Serial1/0
R3#show clns route
Codes: C - connected, S - static, d - DecnetIV
I - ISO-IGRP, i - IS-IS, e - ES-IS
B - BGP, b - eBGP-neighbor
C 49.0002.3333.3333.3333.00 [1/0], Local IS-IS NET
C 49.0002 [2/0], Local IS-IS Area
i 49.0001 [110/10]
via R2, Serial1/0
show clns route是用来查看L2的路由信息，因为R1为L1的路由器，所以在R1上看不到有关L2的信息， 但是在R2 R3上能看到一条L2的路由信息。下面在R1上进行ping验证：
R1#ping clns 49.0002.3333.3333.3333.00
Type escape sequence to abort.
Sending 5, 100-byte CLNS Echos with timeout 2 seconds
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 192/241/344 ms
通了，可以到R3。
实验总结：掌握基本的ISIS配置和一些验证ISIS配置正确的命令。
本文转自loveme2351CTO博客，原文链接：http://blog.51cto.com/loveme23/47877 ，如需转载请自行联系原作者
