IS-IS与OSPF很像，ospf多用于企业网络中，ISIS多用于ISP运营商。ISIS服务于OSI中，OSPF服务于TCP/IP中（集成ISIS除外，兼容两种网络模型）。ISIS的收敛速度比OSPF快。
IS-IS在IP网络运行IS-IS时，只需配置NET，根据NET地址设备可以和获取到Area ID 以及system ID（类似于OSPF的router ID）.区域号的作用为判断是否在同一区域，作用于L1，于OSPF不同，区域号0不是骨干区域，ISIS的骨干区域是由L1/L2路由器和L2路由器组成的区域，不看区域号是否相同或者为0000。
其中：
49代表私网区域，47代表公网区域。0001代表区域1
IS-IS基础实验：
ISIS和OSPF一样有三张表：
1）ISIS-邻接表
[R1]display isis peer
2）ISIS-LSDB，和OSPF LSDB非常相似，LSP类似于LSA，只存在类似OSPF中的1类、2类和5类的LSA，没有3，4，7类LSA
[R1]display isis lsdb
[R1]display isis lsdb aaaa.aaaa.aaaa.00 verbose
3）ISIS-路由表
[R1]display isis route
ISIS中有三种级别的路由器，用于定义ISIS的骨干区域和非骨干区域
1)level-1路由器
2)level-2路由器
3)level-1/2路由器（默认）
可以理解为level-1-2夹在中间，level-1看level-1-2只有level-1的信息。Level-2看level-1-2只有level-2的信息。但level-1/2路由器又有个功能即是将level-1的路由信息转换为level-2.
两边都是Level-1/2路由器，所以在每台 dis isis peer breif中有各有两条，对应的是level-1和level-2
OSPF和ISIS的不同，
在OSPF中，骨干区域-area0有且只有一个area0。所有非骨干区域和骨干区域相接，非骨干区域不能相连。在ospf中，骨干区域和非骨干区域通过ABR相连接；
在ISIS中，level2骨干区域有level-2路由器构建的区域，非骨干区域有level1路由器构建的区域。有且只有一个骨干区域，所有非骨干区域和骨干区域相接，非骨干区域不能相连。在ISIS中，骨干区域和非骨干区域通过level1/2相连接；也就是level-1-2和level-2相接，不管是否在同一区域中。
它们之间建立的是Level-2邻接，交换的是Level-2 LSP。这正是骨干区域的本质。一个连续的骨干网可以由同一个区域ID下的多个L2和L1/2路由器组成。R1和R3作为L1/2路由器，同时还承担着连接各自Level-1区域（未画出）的任务。
关键点：
尽管它们的区域ID不同，但只要它们之间能够建立Level-2邻接，它们就属于同一个骨干区域。
数据包从Area 49.001去往Area 49.003，正是在这个跨越不同区域ID的骨干区域中进行转发的。
对于R1和R3来说，它们身兼两职：
作为骨干区域成员，与R2交换L2 LSP。
作为区域边界，向各自所在的Level-1区域（Area 49.001和Area 49.003）通告默认路由。
Level-2只会有级别2的LSDB，level-1只会有级别1的LSDB
调整路由器级别命令
[R1]isis 15
[R1-isis-15]is-level level-1
OSPF的区域是基于端口，而ISIS骨干区域是基于设备。这是非常大的不同。
IS-IS实验
以下两个实验主要观察所有等级路由器在相同及不同区域中lsdb、不同区域下的是否会生成0.0.0.0 的默认路由、路由表介绍及LSP分析。
铁律：ISIS建立邻居关系时的硬性要求：
1）Level-1路由器和level-1路由器建立L1的领居关系；
2）level-2路由器和level-2路由器建立L2的领居关系；
3）L1领居必须区域号一定要相同，但L2领居关系无区域号相同的规则；
当Level-1-2路由器连接到另一个L2区域的L2路由器，L1/L2才会向L1区域下放一条0.0.0.0 的默认路由，这个行为特别像OSPF的stub区域中的ABR行为。
非骨干区域L1默认情况下是不会知道L2的骨干区域的明细路由，但骨干区域L2默认情况下是知道L1非骨干区域的明细路由，这个行为特别像OSPF的stub 末节区域只有0.0.0.0/0的默认路由，而area 0则拥有完整的各个区域号的明细路由一样。只是isis这个行为是默认的。L2不管是在相同区域还是不同区域中都有L1的的路由信息
L1、L1/L2、L2路由器在相同区域下
R1的配置如下：
[Huawei]sys R1
[R1]isis 15
[R1-isis-15]network-entity 49.0000.1111.1111.1111.00
[R1-isis-15]is-level level-1
[R1]int g0/0/1
[R1-GigabitEthernet0/0/1]ip add 12.1.1.1 24
[R1-GigabitEthernet0/0/1]isis enable 15
R2的配置如下：
[Huawei]sys R2
[R2]isis 15
[R2-isis-15]network-entity 49.0000.2222.2222.2222.00
[R2-isis-15]is-level level-1
[R2]int g0/0/0
[R2-GigabitEthernet0/0/0]ip add 12.1.1.2 24
[R2-GigabitEthernet0/0/0]isis enable 15
[R2-GigabitEthernet0/0/0]int g0/0/1
[R2-GigabitEthernet0/0/1]ip add 23.1.1.2 24
[R2-GigabitEthernet0/0/1]isis enable 15
R3的配置如下：
[Huawei]sys R3
[R3]isis 15
[R3-isis-15]network-entity 49.0000.3333.3333.3333.00 //默认情况下是L1/L2的路由器
[R3]int g0/0/0
[R3-GigabitEthernet0/0/0]ip add 23.1.1.3 24
[R3-GigabitEthernet0/0/0]isis enable 15
[R3-GigabitEthernet0/0/0]int g0/0/1
[R3-GigabitEthernet0/0/1]ip add 34.1.1.3 24
[R3-GigabitEthernet0/0/1]isis enable 15
R4的配置如下：
[Huawei]sys R4
[R4]isis 15
[R4-isis-15]network-entity 49.0000.4444.4444.4444.00
[R4-isis-15]is-level level-2
[R4-GigabitEthernet0/0/0]ip add 34.1.1.4 24
[R4-GigabitEthernet0/0/0]isis enable 15
此时R1的路由表
<R1>dis ip routing-table
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: Public
Destinations : 9 Routes : 9
Destination/Mask Proto Pre Cost Flags NextHop Interface
12.1.1.0/24 Direct 0 0 D 12.1.1.1 GigabitEthernet
0/0/1
12.1.1.1/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/1
12.1.1.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/1
23.1.1.0/24 ISIS-L1 15 20 D 12.1.1.2 GigabitEthernet
0/0/1
34.1.1.0/24 ISIS-L1 15 30 D 12.1.1.2 GigabitEthernet
0/0/1
127.0.0.0/8 Direct 0 0 D 127.0.0.1 InLoopBack0
127.0.0.1/32 Direct 0 0 D 127.0.0.1 InLoopBack0
127.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0
255.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0
R2的LSDB数据库及LSP 2222.2222.2222.00-00 内容信息，其中后面带*为本设备发出，xxxx.xxxx.xxxx.00-00 类似于OSPF的1类LSA，描述路由信息和拓扑信息，xxxx.xxxx.xxxx.01-00 类似于OSPF的2类LSA，是DR描述对端信息。
[R2]dis isis lsdb
Database information for ISIS(15)
---------------------------------
Level-1 Link State Database
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
-------------------------------------------------------------------------------
1111.1111.1111.00-00 0x00000004 0x2411 592 70 0/0/0
1111.1111.1111.01-00 0x00000001 0x7483 591 55 0/0/0
2222.2222.2222.00-00* 0x00000006 0x35fb 707 97 0/0/0
3333.3333.3333.00-00 0x00000005 0x396 776 86 0/0/0
3333.3333.3333.01-00 0x00000001 0xa9b2 726 55 0/0/0
查看LSP 2222.2222.2222.00-00信息
[R2]dis isis lsdb 2222.2222.2222.00-00 verbose
Database information for ISIS(15)
---------------------------------
Level-1 Link State Database
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
-------------------------------------------------------------------------------
2222.2222.2222.00-00* 0x00000006 0x35fb 549 97 0/0/0
SOURCE 2222.2222.2222.00
NLPID IPV4
AREA ADDR 49.0000 //区域为49.0000
INTF ADDR 12.1.1.2 //接口IP地址为12.1.1.2
INTF ADDR 23.1.1.2 //另一个接口IP地址为23.1.1.2
NBR ID 1111.1111.1111.01 COST: 10 //邻居路由器1111.1111.1111.01，链路代价10
NBR ID 3333.3333.3333.01 COST: 10 //邻居路由器3333.3333.3333.01，链路代价10
IP-Internal 12.1.1.0 255.255.255.0 COST: 10 //本段路由的网段为12.1.1.0，掩码为24位本接口花销等于10
IP-Internal 23.1.1.0 255.255.255.0 COST: 10 //本段路由的网段为23.1.1.0，掩码为24位本接口花销等于10
[R2]dis isis lsdb 3333.3333.3333.01-00 verbose
Database information for ISIS(15)
---------------------------------
Level-1 Link State Database
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
-------------------------------------------------------------------------------
3333.3333.3333.01-00 0x00000002 0xa7b3 1145 55 0/0/0
SOURCE 3333.3333.3333.01
NLPID IPV4
NBR ID 3333.3333.3333.00 COST: 0 //一端的system ID，花销0
NBR ID 2222.2222.2222.00 COST: 0 //另一端的system ID，花销0
查看路由表，34.1.1.0/24 ISIS-L1 //34.1.1.0/24 花销计算是：R2->R3。因为R2到R3的IP-Internal cost值为10，加上NBR ID 3333.3333.3333.01 COST: 10 链路代价10，就是10+10=20，而不是计算R2->R3->R4的入接口开销，因为L1无法到达L2
[R2]dis ip routing-table
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: Public
Destinations : 11 Routes : 11
Destination/Mask Proto Pre Cost Flags NextHop Interface
12.1.1.0/24 Direct 0 0 D 12.1.1.2 GigabitEthernet
0/0/0
12.1.1.2/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0
12.1.1.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0
23.1.1.0/24 Direct 0 0 D 23.1.1.2 GigabitEthernet
0/0/1
23.1.1.2/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/1
23.1.1.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/1
34.1.1.0/24 ISIS-L1 15 20 D 23.1.1.3 GigabitEthernet
0/0/1
127.0.0.0/8 Direct 0 0 D 127.0.0.1 InLoopBack0
127.0.0.1/32 Direct 0 0 D 127.0.0.1 InLoopBack0
127.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0
255.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0
R3是L1/L2，此时将会有有两份LSDB，一份L1 LSDB，一份L2 LSDB。
<R3>dis isis lsdb
Database information for ISIS(15)
---------------------------------
Level-1 Link State Database
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
-------------------------------------------------------------------------------
1111.1111.1111.00-00 0x00000008 0x1c15 821 70 0/0/0
1111.1111.1111.01-00 0x00000005 0x6c87 821 55 0/0/0
2222.2222.2222.00-00 0x0000000a 0x2dff 933 97 0/0/0
3333.3333.3333.00-00* 0x00000009 0xfa9a 834 86 0/0/0
3333.3333.3333.01-00* 0x00000005 0xa1b6 834 55 0/0/0
Total LSP(s): 5
*(In TLV)-Leaking Route, *(By LSPID)-Self LSP, +-Self LSP(Extended),
ATT-Attached, P-Partition, OL-Overload
Level-2 Link State Database
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
-------------------------------------------------------------------------------
3333.3333.3333.00-00* 0x0000000b 0x8d55 834 98 0/0/0
3333.3333.3333.02-00* 0x00000005 0x189 834 55 0/0/0
4444.4444.4444.00-00 0x00000008 0xe21c 840 70 0/0/0
Total LSP(s): 3
*(In TLV)-Leaking Route, *(By LSPID)-Self LSP, +-Self LSP(Extended),
ATT-Attached, P-Partition, OL-Overload
此时R3路由表，只有12.1.1.0/24，因为其他都是直连路由，无需通过IS-IS
<R3>dis ip routing-table
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: Public
Destinations : 11 Routes : 11
Destination/Mask Proto Pre Cost Flags NextHop Interface
12.1.1.0/24 ISIS-L1 15 20 D 23.1.1.2 GigabitEthernet
0/0/0
23.1.1.0/24 Direct 0 0 D 23.1.1.3 GigabitEthernet
0/0/0
23.1.1.3/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0
23.1.1.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0
34.1.1.0/24 Direct 0 0 D 34.1.1.3 GigabitEthernet
0/0/1
34.1.1.3/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/1
34.1.1.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/1
127.0.0.0/8 Direct 0 0 D 127.0.0.1 InLoopBack0
127.0.0.1/32 Direct 0 0 D 127.0.0.1 InLoopBack0
127.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0
255.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0
R4 LSDB如下所示：
[R4]dis isis lsdb
Database information for ISIS(15)
---------------------------------
Level-2 Link State Database
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
-------------------------------------------------------------------------------
3333.3333.3333.00-00 0x00000007 0x9551 1152 98 0/0/0
3333.3333.3333.02-00 0x00000001 0x985 1152 55 0/0/0
4444.4444.4444.00-00* 0x00000004 0xea18 1173 70 0/0/0
此时查看LSP 3333.3333.3333.00-00，可以看到L1的路由信息
[R4]dis isis lsdb 3333.3333.3333.00-00 verbose
Database information for ISIS(15)
---------------------------------
Level-2 Link State Database
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
-------------------------------------------------------------------------------
3333.3333.3333.00-00 0x00000007 0x9551 1053 98 0/0/0
SOURCE 3333.3333.3333.00
NLPID IPV4
AREA ADDR 49.0000
INTF ADDR 23.1.1.3
INTF ADDR 34.1.1.3
NBR ID 3333.3333.3333.02 COST: 10
IP-Internal 23.1.1.0 255.255.255.0 COST: 10
IP-Internal 12.1.1.0 255.255.255.0 COST: 20
IP-Internal 34.1.1.0 255.255.255.0 COST: 10
Total LSP(s): 1
*(In TLV)-Leaking Route, *(By LSPID)-Self LSP, +-Self LSP(Extended),
ATT-Attached, P-Partition, OL-Overload
DR信息
[R4]dis isis lsdb 3333.3333.3333.02-00 verbose
Database information for ISIS(15)
---------------------------------
Level-2 Link State Database
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
-------------------------------------------------------------------------------
3333.3333.3333.02-00 0x00000001 0x985 1111 55 0/0/0
SOURCE 3333.3333.3333.02
NLPID IPV4
NBR ID 3333.3333.3333.00 COST: 0
NBR ID 4444.4444.4444.00 COST: 0
Total LSP(s): 1
*(In TLV)-Leaking Route, *(By LSPID)-Self LSP, +-Self LSP(Extended),
ATT-Attached, P-Partition, OL-Overload
[R4]dis isis lsdb 4444.4444.4444.00-00 verbose
Database information for ISIS(15)
---------------------------------
Level-2 Link State Database
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
-------------------------------------------------------------------------------
4444.4444.4444.00-00* 0x00000004 0xea18 1010 70 0/0/0
SOURCE 4444.4444.4444.00
NLPID IPV4
AREA ADDR 49.0000
INTF ADDR 34.1.1.4
NBR ID 3333.3333.3333.02 COST: 10
IP-Internal 34.1.1.0 255.255.255.0 COST: 10
Total LSP(s): 1
*(In TLV)-Leaking Route, *(By LSPID)-Self LSP, +-Self LSP(Extended),
ATT-Attached, P-Partition, OL-Overload
此时的R4，在路由表中是可以看到12.1.1.0/24网段，23.1.1.0/24网段，但是已L2的路由器引入。
[R4]dis ip routing-table
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: Public
Destinations : 9 Routes : 9
Destination/Mask Proto Pre Cost Flags NextHop Interface
12.1.1.0/24 ISIS-L2 15 30 D 34.1.1.3 GigabitEthernet
0/0/0
23.1.1.0/24 ISIS-L2 15 20 D 34.1.1.3 GigabitEthernet
0/0/0
34.1.1.0/24 Direct 0 0 D 34.1.1.4 GigabitEthernet
0/0/0
34.1.1.4/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0
34.1.1.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0
127.0.0.0/8 Direct 0 0 D 127.0.0.1 InLoopBack0
127.0.0.1/32 Direct 0 0 D 127.0.0.1 InLoopBack0
127.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0
255.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0
L1和L1/L2于L2不在一个区域
R1路由器配置
<Huawei>sys
[Huawei]sys R1
[R1]isis 15
[R1-isis-15]network-entity 49.0000.1111.1111.1111.00
[R1-isis-15]is-level level-1
[R1-isis-15]int g0/0/0
[R1-GigabitEthernet0/0/0]ip add 12.1.1.1 24
[R1-GigabitEthernet0/0/0]isis enable 15
[R1]dis isis lsdb
R2路由器配置
<Huawei>sys
[Huawei]sys R2
[R2]isis 15
[R2-isis-15]network-entity 49.0000.2222.2222.2222.00
[R2-isis-15]is-level level-1
[R2-isis-15]int g0/0/0
[R2-GigabitEthernet0/0/0]ip add 12.1.1.2 24
[R2-GigabitEthernet0/0/0]isis enable 15
[R2-GigabitEthernet0/0/0]int g0/0/1
[R2-GigabitEthernet0/0/1]ip add 23.1.1.2 24
[R2-GigabitEthernet0/0/1]isis enable 15
[R2-GigabitEthernet0/0/1]q
R3路由器配置
<Huawei>sys
[Huawei]sys R3
[R3]isis 15
[R3-isis-15]network-entity 49.0000.3333.3333.3333.00
[R3-isis-15]int g0/0/0
[R3-GigabitEthernet0/0/0]ip add 23.1.1.3 24
[R3-GigabitEthernet0/0/0]isis enable 15
[R3-GigabitEthernet0/0/0]int g0/0/1
[R3-GigabitEthernet0/0/1]ip add 34.1.1.3 24
[R3-GigabitEthernet0/0/1]isis enable 15
R4路由器配置
<Huawei>sys
[Huawei]sys R4
[R4]isis 15
[R4-isis-15]network-entity 49.0001.4444.4444.4444.00
[R4-isis-15]is-level level-2
[R4-isis-15]q
[R4]int g0/0/0
[R4-GigabitEthernet0/0/0]ip add 34.1.1.4 24
[R4-GigabitEthernet0/0/0]isis enable 15
R1的LSDB
Database information for ISIS(15)
---------------------------------
Level-1 Link State Database
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
-------------------------------------------------------------------------------
1111.1111.1111.00-00* 0x00000005 0x5578 878 70 0/0/0
2222.2222.2222.00-00 0x00000007 0xef3f 875 97 0/0/0
2222.2222.2222.01-00 0x00000003 0xd6b8 875 55 0/0/0
2222.2222.2222.02-00 0x00000003 0x368b 875 55 0/0/0
3333.3333.3333.00-00 0x00000008 0xad48 980 86 1/0/0
R1的路由表，此时会多出一条由L1/L2路由器发出的一条0.0.0.0的默认路由。（重中之重）
[R1]dis ip routing-table
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: Public
Destinations : 10 Routes : 10
Destination/Mask Proto Pre Cost Flags NextHop Interface
0.0.0.0/0 ISIS-L1 15 20 D 12.1.1.2 GigabitEthernet
0/0/0
12.1.1.0/24 Direct 0 0 D 12.1.1.1 GigabitEthernet
0/0/0
12.1.1.1/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0
12.1.1.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0
23.1.1.0/24 ISIS-L1 15 20 D 12.1.1.2 GigabitEthernet
0/0/0
34.1.1.0/24 ISIS-L1 15 30 D 12.1.1.2 GigabitEthernet
0/0/0
127.0.0.0/8 Direct 0 0 D 127.0.0.1 InLoopBack0
127.0.0.1/32 Direct 0 0 D 127.0.0.1 InLoopBack0
127.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0
255.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0
R2的LSDB 数据库
<R2>dis isis lsdb
Database information for ISIS(15)
---------------------------------
Level-1 Link State Database
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
-------------------------------------------------------------------------------
1111.1111.1111.00-00 0x00000008 0x4f7b 963 70 0/0/0
2222.2222.2222.00-00* 0x0000000a 0xe942 1095 97 0/0/0
2222.2222.2222.01-00* 0x00000006 0xd0bb 1095 55 0/0/0
2222.2222.2222.02-00* 0x00000006 0x308e 1095 55 0/0/0
3333.3333.3333.00-00 0x0000000b 0xa74b 1166 86 1/0/0
R2的路由表，此处与R1相同。
<R2>dis ip routing-table
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: Public
Destinations : 12 Routes : 12
Destination/Mask Proto Pre Cost Flags NextHop Interface
0.0.0.0/0 ISIS-L1 15 10 D 23.1.1.1 GigabitEthernet
0/0/1
12.1.1.0/24 Direct 0 0 D 12.1.1.2 GigabitEthernet
0/0/0
12.1.1.2/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0
12.1.1.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0
23.1.1.0/24 Direct 0 0 D 23.1.1.2 GigabitEthernet
0/0/1
23.1.1.2/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/1
23.1.1.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/1
34.1.1.0/24 ISIS-L1 15 20 D 23.1.1.1 GigabitEthernet
0/0/1
127.0.0.0/8 Direct 0 0 D 127.0.0.1 InLoopBack0
127.0.0.1/32 Direct 0 0 D 127.0.0.1 InLoopBack0
127.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0
255.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0
R3为L1/L2路由器，所以有两个LSDB。
<R3>dis isis lsdb
Database information for ISIS(15)
---------------------------------
Level-1 Link State Database
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
-------------------------------------------------------------------------------
1111.1111.1111.00-00 0x00000008 0x4f7b 916 70 0/0/0
2222.2222.2222.00-00 0x0000000a 0xe942 1049 97 0/0/0
2222.2222.2222.01-00 0x00000006 0xd0bb 1049 55 0/0/0
2222.2222.2222.02-00 0x00000006 0x308e 1049 55 0/0/0
3333.3333.3333.00-00* 0x0000000b 0xa74b 1122 86 1/0/0
Total LSP(s): 5
*(In TLV)-Leaking Route, *(By LSPID)-Self LSP, +-Self LSP(Extended),
ATT-Attached, P-Partition, OL-Overload
Level-2 Link State Database
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
-------------------------------------------------------------------------------
3333.3333.3333.00-00* 0x0000000f 0x4997 1122 98 0/0/0
3333.3333.3333.02-00* 0x00000007 0xfc8b 1122 55 0/0/0
4444.4444.4444.00-00 0x00000009 0xea12 1062 70 0/0/0
Total LSP(s): 3
*(In TLV)-Leaking Route, *(By LSPID)-Self LSP, +-Self LSP(Extended),
ATT-Attached, P-Partition, OL-Overload
<R3>dis ip routing-table
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: Public
Destinations : 11 Routes : 11
Destination/Mask Proto Pre Cost Flags NextHop Interface
12.1.1.0/24 ISIS-L1 15 20 D 23.1.1.2 GigabitEthernet
0/0/0
23.1.1.0/24 Direct 0 0 D 23.1.1.1 GigabitEthernet
0/0/0
23.1.1.1/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0
23.1.1.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0
34.1.1.0/24 Direct 0 0 D 34.1.1.3 GigabitEthernet
0/0/1
34.1.1.3/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/1
34.1.1.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/1
127.0.0.0/8 Direct 0 0 D 127.0.0.1 InLoopBack0
127.0.0.1/32 Direct 0 0 D 127.0.0.1 InLoopBack0
127.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0
255.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0
R4LSDB如下所示
<R4>dis isis lsdb
Database information for ISIS(15)
---------------------------------
Level-2 Link State Database
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
-------------------------------------------------------------------------------
3333.3333.3333.00-00 0x0000000f 0x4997 1080 98 0/0/0
3333.3333.3333.02-00 0x00000007 0xfc8b 1080 55 0/0/0
4444.4444.4444.00-00* 0x00000009 0xea12 1023 70 0/0/0
Total LSP(s): 3
*(In TLV)-Leaking Route, *(By LSPID)-Self LSP, +-Self LSP(Extended),
ATT-Attached, P-Partition, OL-Overload
R4 路由表如下所示
<R4>dis ip routing-table
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: Public
Destinations : 9 Routes : 9
Destination/Mask Proto Pre Cost Flags NextHop Interface
12.1.1.0/24 ISIS-L2 15 30 D 34.1.1.3 GigabitEthernet
0/0/0
23.1.1.0/24 ISIS-L2 15 20 D 34.1.1.3 GigabitEthernet
0/0/0
34.1.1.0/24 Direct 0 0 D 34.1.1.4 GigabitEthernet
0/0/0
34.1.1.4/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0
34.1.1.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0
127.0.0.0/8 Direct 0 0 D 127.0.0.1 InLoopBack0
127.0.0.1/32 Direct 0 0 D 127.0.0.1 InLoopBack0
127.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0
255.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0
ISIS的网络类型
分为2种，一种为P2P一种为广播型。
ISIS花销值
ISIS使用cost作为路由度量值，cost值越小越优，isis cost与设备接口有关，缺省情况下路由花销值默认为10。
路由的cost值=路由传递的入方向的累积，环回接口cost-0，当进入R1时，总花销=0+10=10，所以在R1的路由表中查看花销时2.2.2.2/32总花销等于10
选路优先级L1>L2（类似于OSPF的选路规则，L1约等于OSPF的域内，L2约等于OSPF的域间，域内>域间）
在早期的ISO10589中，使能IS-IS的接口下最大只能配置值为63的开销值，此时IS-IS的开销类型为narrow。（窄）
但是在大型网络设计中，较小的度量范围不能满足实际需求。RFC3784中规定，使能IS-IS的接口开销值可以扩展到16777215，此时IS-IS的开销类型为wide。（宽）
缺省时，华为路由器采用的开销类型是narrow。(窄）两种度量值不能混用，如果混用。路由无法正常计算
[R1]isis 15
[R1-isis15]cost-type wide
[R2]isis 15
[R2-isis15]cost-type narrow //此时将收不到2.2.2.2/32的路由信息
[R2-isis15]cost-type wide //调整为wide后就可以正常接收2.2.2.2/32路由信息
宽度量值最重要的作用是可以增加路由标记tag。tag用来标明具有相同特性的一组路由。
DIS
相当于OSPF的DR，DIS在邻居表的Circuit Id查看，后缀为01、02等非00表示。
1）DIS的默认优先级为64；
2）DIS的选举规则抢占；
3）接口的优先级越大越优，当优先级相同时，接口的MAC地址越大越优。其中在isis-peer 中的PRI优先级是对端优先级；
4）OSPF中DR优先级为0为放弃选举，但在ISIS优先级为0仍然参与选举；
[R1]dis isis peer
Peer information for ISIS(15)
System Id Interface Circuit Id State HoldTime Type PRI
-------------------------------------------------------------------------------
bbbb.bbbb.bbbb GE0/0/0 bbbb.bbbb.bbbb.01 Up 7s L1(L1L2) 64
bbbb.bbbb.bbbb GE0/0/0 bbbb.bbbb.bbbb.01 Up 8s L2(L1L2) 64
[R1-G 0/0/0]isis dis-priority 65 //当此处在配置时未指定level-1或level-2时，则会将所有等级优先级设置为65
此时R1中L1和L2中的DIS从原来的bbbb.bbbb.bbbb.01全部修改为aaaa.aaaa.aaaa.01
Peer information for ISIS(15)
System Id Interface Circuit Id State HoldTime Type PRI
-------------------------------------------------------------------------------
bbbb.bbbb.bbbb GE0/0/0 aaaa.aaaa.aaaa.01 Up 29s L1(L1L2) 64
bbbb.bbbb.bbbb GE0/0/0 aaaa.aaaa.aaaa.01 Up 29s L2(L1L2) 64
[R1-G 0/0/0]isis dis-priority 65 level-1 //只修改Level-1的优先级
[R1]dis isis peer
Peer information for ISIS(15)
System Id Interface Circuit Id State HoldTime Type PRI
-------------------------------------------------------------------------------
bbbb.bbbb.bbbb GE0/0/0 aaaa.aaaa.aaaa.01 Up 24s L1(L1L2) 64
bbbb.bbbb.bbbb GE0/0/0 bbbb.bbbb.bbbb.01 Up 9s L2(L1L2) 64
ISIS--计时器
普通的ISIS路由器的hello间隔为10s一次；
普通的ISIS路由器Dead间隔为30s一次；
DIS ISIS每隔10S周期性泛洪CSNP同步LSDB，如果ISIS中有路由器缺少的LSP，那么发送PSNP请求即可同步数据库。
DIS ISIS路由器hello间隔为3.3s一次；
DIS ISIS路由器Dead间隔为10s一次。
R1为L1的DIS ，R2为L2的DIS。此时断开R2的线，则R1的L2在10秒后就会失去R2的L2邻居关系，而R1的L1会在30秒后失去R2的L1的邻居关系。
<R1>dis isis peer
Peer information for ISIS(15)
System Id Interface Circuit Id State HoldTime Type PRI
-------------------------------------------------------------------------------
bbbb.bbbb.bbbb GE0/0/0 aaaa.aaaa.aaaa.01 Up 25s L1(L1L2) 64
bbbb.bbbb.bbbb GE0/0/0 bbbb.bbbb.bbbb.01 Up 7s L2(L1L2) 64
<R2>dis isis peer
Peer information for ISIS(15)
System Id Interface Circuit Id State HoldTime Type PRI
-------------------------------------------------------------------------------
aaaa.aaaa.aaaa GE0/0/0 aaaa.aaaa.aaaa.01 Up 7s L1(L1L2) 65
aaaa.aaaa.aaaa GE0/0/0 bbbb.bbbb.bbbb.01 Up 30s L2(L1L2) 64
ISIS邻居建立过程
广播网络中的邻接关系建立
发送IIH报文，发送前neighbour=null，当对端未收到IIH时，状态为DOWN，当收到IIH报文后，状态变为Initial，且发送IIH，此IIH中的neighbour 填写对端的路由器的MAC地址，当路由器收到带有自己mac地址的IIH报文后，接口状态变为UP，同时发送带有对端的MAC地址的IIH，当对端接收到后，接口状态改为UP。（和OSPF 建立2-Way很像，只是将对端的RID改为对端的MAC地址）
点到点中的邻接关系建立
发送IIH报文，发送前neighbour=null，当对端未收到IIH时，状态为DOWN，当收到IIH报文后，状态变为Initial，且发送IIH，此IIH中的neighbour 填写对端的路由器的system ID，当路由器收到带有自己mac地址的IIH报文后，接口状态变为UP，同时发送带有对端的system ID的IIH，当对端接收到后，接口状态改为UP。（和OSPF 建立2-Way很像，只是将对端的RID改为对端的system ID）
ISIS的LSDB
广播型 #还需要在做个level-1的实验
<R1>dis isis peer
Peer information for ISIS(15)
System Id Interface Circuit Id State HoldTime Type PRI
-------------------------------------------------------------------------------
bbbb.bbbb.bbbb GE0/0/0 aaaa.aaaa.aaaa.01 Up 26s L1(L1L2) 64
bbbb.bbbb.bbbb GE0/0/0 bbbb.bbbb.bbbb.01 Up 8s L2(L1L2) 64
<R2>dis isis peer
Peer information for ISIS(15)
System Id Interface Circuit Id State HoldTime Type PRI
-------------------------------------------------------------------------------
aaaa.aaaa.aaaa GE0/0/0 aaaa.aaaa.aaaa.01 Up 9s L1(L1L2) 65 //对端的优先级
aaaa.aaaa.aaaa GE0/0/0 bbbb.bbbb.bbbb.01 Up 24s L2(L1L2) 64
<R1>dis isis lsdb
Database information for ISIS(15)
---------------------------------
Level-1 Link State Database
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
-------------------------------------------------------------------------------
aaaa.aaaa.aaaa.00-00* 0x0000001c 0xf5f1 787 70 0/0/0
aaaa.aaaa.aaaa.01-00* 0x0000000d 0x918b 787 55 0/0/0
bbbb.bbbb.bbbb.00-00 0x0000001a 0xe49d 556 70 0/0/0
Total LSP(s): 3
*(In TLV)-Leaking Route, *(By LSPID)-Self LSP, +-Self LSP(Extended),
ATT-Attached, P-Partition, OL-Overload
Level-2 Link State Database
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
-------------------------------------------------------------------------------
aaaa.aaaa.aaaa.00-00* 0x0000001d 0x2759 787 70 0/0/0
bbbb.bbbb.bbbb.00-00 0x0000001d 0x1207 556 70 0/0/0
bbbb.bbbb.bbbb.01-00 0x00000011 0xefc2 556 55 0/0/0
<R1>dis isis lsdb bbbb.bbbb.bbbb.00-00 verbose
Database information for ISIS(15)
---------------------------------
Level-1 Link State Database
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
-------------------------------------------------------------------------------
bbbb.bbbb.bbbb.00-00 0x0000001b 0xe29e 721 70 0/0/0
SOURCE bbbb.bbbb.bbbb.00
NLPID IPV4
AREA ADDR 49.0000
INTF ADDR 12.1.1.2
NBR ID aaaa.aaaa.aaaa.01 COST: 10
IP-Internal 12.1.1.0 255.255.255.0 COST: 10
Total LSP(s): 1
*(In TLV)-Leaking Route, *(By LSPID)-Self LSP, +-Self LSP(Extended),
ATT-Attached, P-Partition, OL-Overload
Level-2 Link State Database
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
-------------------------------------------------------------------------------
bbbb.bbbb.bbbb.00-00 0x0000001e 0x1008 721 70 0/0/0
SOURCE bbbb.bbbb.bbbb.00
NLPID IPV4
AREA ADDR 49.0000
INTF ADDR 12.1.1.2
NBR ID bbbb.bbbb.bbbb.01 COST: 10
IP-Internal 12.1.1.0 255.255.255.0 COST: 10
Total LSP(s): 1
*(In TLV)-Leaking Route, *(By LSPID)-Self LSP, +-Self LSP(Extended),
ATT-Attached, P-Partition, OL-Overload
[R1]dis isis lsdb bbbb.bbbb.bbbb.01-00 verbose
Database information for ISIS(15)
---------------------------------
Level-2 Link State Database
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
-------------------------------------------------------------------------------
bbbb.bbbb.bbbb.01-00 0x00000012 0xedc3 613 55 0/0/0
SOURCE bbbb.bbbb.bbbb.01
NLPID IPV4
NBR ID bbbb.bbbb.bbbb.00 COST: 0
NBR ID aaaa.aaaa.aaaa.00 COST: 0
Total LSP(s): 1
*(In TLV)-Leaking Route, *(By LSPID)-Self LSP, +-Self LSP(Extended),
ATT-Attached, P-Partition, OL-Overload
P2P：
在R3上配置了两个环回接口2.2.2.2/32和22.22.22.22/32并宣告进isis 15.
R3路由器配置
<Huawei>sys
[Huawei]sys R3
[R3]isis 15
[R3-isis-15]network-entity 49.0000.cccc.cccc.cccc.00
[R3-isis-15]q
[R3]int g0/0/0
[R3-GigabitEthernet0/0/0]ip add 34.1.1.3 24
[R3-GigabitEthernet0/0/0]isis enable 15
[R3-GigabitEthernet0/0/0]isis circuit-type p2p
[R3]int LoopBack 0
[R3i-LoopBack0]ip add 2.2.2.2 32
[R3-LoopBack0]isis e 15
[R3-LoopBack0]q
[R3]int LoopBack 1
[R3-LoopBack1]ip add 22.22.22.22 32
[R3-LoopBack1]isis e
[R3-LoopBack1]isis enable 15
R4路由器配置
<Huawei>sys
[Huawei]sys R4
[R4]isis 15
[R4-isis-15]network-entity 49.0000.dddd.dddd.dddd.00
[R4-isis-15]q
[R4]int g0/0/0
[R4-GigabitEthernet0/0/0]ip add 34.1.1.4 24
[R4-GigabitEthernet0/0/0]isis enable 15
[R4-GigabitEthernet0/0/0]isis circuit-type p2p
[R3-LoopBack1]dis isis peer
Peer information for ISIS(15)
System Id Interface Circuit Id State HoldTime Type PRI
-------------------------------------------------------------------------------
dddd.dddd.dddd GE0/0/0 0000000001 Up 29s L1L2 -- //没有优先级
[R4]dis isis peer
Peer information for ISIS(15)
System Id Interface Circuit Id State HoldTime Type PRI
-------------------------------------------------------------------------------
cccc.cccc.cccc GE0/0/0 0000000001 Up 25s L1L2 -- //Circuit Id0000000003是什么情况？
[R3]dis isis lsdb dddd.dddd.dddd.00-00 verbose
Database information for ISIS(15)
---------------------------------
Level-1 Link State Database
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
-------------------------------------------------------------------------------
dddd.dddd.dddd.00-00 0x00000009 0xae20 662 70 0/0/0
SOURCE dddd.dddd.dddd.00
NLPID IPV4
AREA ADDR 49.0000
INTF ADDR 34.1.1.4
NBR ID cccc.cccc.cccc.00 COST: 10
IP-Internal 34.1.1.0 255.255.255.0 COST: 10 （本接口的花销10）
Total LSP(s): 1
*(In TLV)-Leaking Route, *(By LSPID)-Self LSP, +-Self LSP(Extended),
ATT-Attached, P-Partition, OL-Overload
[R4]dis isis lsdb cccc.cccc.cccc.00-00 verbose
Database information for ISIS(15)
---------------------------------
Level-1 Link State Database
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
-------------------------------------------------------------------------------
cccc.cccc.cccc.00-00 0x0000000c 0x4345 1184 102 0/0/0
SOURCE cccc.cccc.cccc.00
NLPID IPV4
AREA ADDR 49.0000
INTF ADDR 34.1.1.3
INTF ADDR 33.33.33.33
INTF ADDR 3.3.3.3
NBR ID dddd.dddd.dddd.00 COST: 10
IP-Internal 34.1.1.0 255.255.255.0 COST: 10
IP-Internal 33.33.33.33 255.255.255.255 COST: 0
IP-Internal 3.3.3.3 255.255.255.255 COST: 0
Total LSP(s): 1
*(In TLV)-Leaking Route, *(By LSPID)-Self LSP, +-Self LSP(Extended),
ATT-Attached, P-Partition, OL-Overload
isis路由引入
路由引入后的花销默认为64！
ISIS路由引入，引用默认为Level-2，需手动修改路由等级 (需做实验，看看R1默认的L1-2，路由表中的查看引入后的L1还是L1)
[R1-isis-15]impore-route static //此时引入level-2
[R1-isis-15]impore-route static level 1 //此时引入level 1
[R1-isis-15]impore-route static level 1-2 //此时引入level 1-2
上面的配置同一区域中的配置：
[R2]int loopBack 0
[R2-LoopBack0]ip add 222.222.222.222 32
[R2]isis 15
[R2-isis-15]impore-route static //若使用此句命令,L1的LSDB查不到如何引入信息，因为R2为L1，路由引入Level默认为Level-2，所以引入无效，需使用impore-route static level 1才可以正常看到引入的路由信息。
[R2-isis-15]import-route direct level-1
此时在Level-1的LSDB将多出一条00.01的LSP，此条就是引入的路由信息，可通过display isis lsdb 2222.2222.2222.00-01 verbose查看详细信息。
[R2]dis isis lsdb
Database information for ISIS(15)
---------------------------------
Level-1 Link State Database
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
-------------------------------------------------------------------------------
1111.1111.1111.00-00 0x0000000a 0x1817 365 70 0/0/0
1111.1111.1111.01-00 0x00000007 0x6889 365 55 0/0/0
2222.2222.2222.00-00* 0x0000000c 0x2902 585 97 0/0/0
2222.2222.2222.00-01* 0x00000001 0xda89 1180 41 0/0/0
3333.3333.3333.00-00 0x0000000c 0xf49d 1193 86 0/0/0
3333.3333.3333.01-00 0x00000008 0x9bb9 1193 55 0/0/0
Total LSP(s): 6
*(In TLV)-Leaking Route, *(By LSPID)-Self LSP, +-Self LSP(Extended),
ATT-Attached, P-Partition, OL-Overload
[R2]display isis lsdb 2222.2222.2222.00-01 verbose
Database information for ISIS(15)
---------------------------------
Level-1 Link State Database
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
-------------------------------------------------------------------------------
2222.2222.2222.00-01* 0x00000002 0xd88a 476 41 0/0/0
SOURCE 2222.2222.2222.00
IP-External 222.222.222.222 255.255.255.255 COST: 64
Total LSP(s): 1
*(In TLV)-Leaking Route, *(By LSPID)-Self LSP, +-Self LSP(Extended),
ATT-Attached, P-Partition, OL-Overload
此时查看R4的lsdb 关于R3 的LSP，则会发现此引入的路由信息。
[R4]dis isis lsdb 3333.3333.3333.00-00 verbose
Database information for ISIS(15)
---------------------------------
Level-2 Link State Database
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
-------------------------------------------------------------------------------
3333.3333.3333.00-00 0x00000010 0x42c5 903 112 0/0/0
SOURCE 3333.3333.3333.00
NLPID IPV4
AREA ADDR 49.0000
INTF ADDR 23.1.1.3
INTF ADDR 34.1.1.3
NBR ID 3333.3333.3333.02 COST: 10
IP-Internal 23.1.1.0 255.255.255.0 COST: 10
IP-Internal 12.1.1.0 255.255.255.0 COST: 20
IP-Internal 34.1.1.0 255.255.255.0 COST: 10
IP-External 222.222.222.222 255.255.255.255 COST: 74
Total LSP(s): 1
*(In TLV)-Leaking Route, *(By LSPID)-Self LSP, +-Self LSP(Extended),
ATT-Attached, P-Partition, OL-Overload
不同区域
[R2]dis isis lsdb
Database information for ISIS(15)
---------------------------------
Level-1 Link State Database
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
-------------------------------------------------------------------------------
1111.1111.1111.00-00 0x00000004 0x5777 445 70 0/0/0
2222.2222.2222.00-00* 0x00000007 0x34fa 1199 97 0/0/0
2222.2222.2222.00-01* 0x00000002 0xd88a 1199 41 0/0/0
2222.2222.2222.01-00* 0x00000002 0xd8b7 1199 55 0/0/0
2222.2222.2222.02-00* 0x00000002 0x388a 1199 55 0/0/0
3333.3333.3333.00-00 0x00000007 0xaf47 434 86 1/0/0
Total LSP(s): 6
*(In TLV)-Leaking Route, *(By LSPID)-Self LSP, +-Self LSP(Extended),
ATT-Attached, P-Partition, OL-Overload
[R2]dis ip routing-table
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: Public
Destinations : 13 Routes : 13
Destination/Mask Proto Pre Cost Flags NextHop Interface
0.0.0.0/0 ISIS-L1 15 10 D 23.1.1.1 GigabitEthernet
0/0/1
12.1.1.0/24 Direct 0 0 D 12.1.1.2 GigabitEthernet
0/0/0
12.1.1.2/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0
12.1.1.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0
23.1.1.0/24 Direct 0 0 D 23.1.1.2 GigabitEthernet
0/0/1
23.1.1.2/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/1
23.1.1.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/1
34.1.1.0/24 ISIS-L1 15 20 D 23.1.1.1 GigabitEthernet
0/0/1
127.0.0.0/8 Direct 0 0 D 127.0.0.1 InLoopBack0
127.0.0.1/32 Direct 0 0 D 127.0.0.1 InLoopBack0
127.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0
222.222.222.222/32 Direct 0 0 D 127.0.0.1 LoopBack0
255.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0
<R3>dis isis lsdb
Database information for ISIS(15)
---------------------------------
Level-1 Link State Database
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
-------------------------------------------------------------------------------
1111.1111.1111.00-00 0x00000004 0x5777 489 70 0/0/0
2222.2222.2222.00-00 0x00000006 0x36f9 486 97 0/0/0
2222.2222.2222.00-01 0x00000001 0xda89 616 41 0/0/0
2222.2222.2222.01-00 0x00000001 0xdab6 486 55 0/0/0
2222.2222.2222.02-00 0x00000001 0x3a89 475 55 0/0/0
3333.3333.3333.00-00* 0x00000007 0xaf47 479 86 1/0/0
Total LSP(s): 6
*(In TLV)-Leaking Route, *(By LSPID)-Self LSP, +-Self LSP(Extended),
ATT-Attached, P-Partition, OL-Overload
Level-2 Link State Database
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
-------------------------------------------------------------------------------
3333.3333.3333.00-00* 0x00000009 0x838d 618 112 0/0/0
3333.3333.3333.02-00* 0x00000001 0x985 479 55 0/0/0
4444.4444.4444.00-00 0x00000004 0xf40d 478 70 0/0/0
4444.4444.4444.00-01 0x00000001 0xef70 1124 41 0/0/0
Total LSP(s): 4
*(In TLV)-Leaking Route, *(By LSPID)-Self LSP, +-Self LSP(Extended),
ATT-Attached, P-Partition, OL-Overload
<R3>dis ip routing-table
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: Public
Destinations : 13 Routes : 13
Destination/Mask Proto Pre Cost Flags NextHop Interface
12.1.1.0/24 ISIS-L1 15 20 D 23.1.1.2 GigabitEthernet
0/0/0
23.1.1.0/24 Direct 0 0 D 23.1.1.1 GigabitEthernet
0/0/0
23.1.1.1/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0
23.1.1.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0
34.1.1.0/24 Direct 0 0 D 34.1.1.3 GigabitEthernet
0/0/1
34.1.1.3/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/1
34.1.1.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/1
44.44.44.44/32 ISIS-L2 15 74 D 34.1.1.4 GigabitEthernet
0/0/1
127.0.0.0/8 Direct 0 0 D 127.0.0.1 InLoopBack0
127.0.0.1/32 Direct 0 0 D 127.0.0.1 InLoopBack0
127.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0
222.222.222.222/32 ISIS-L1 15 74 D 23.1.1.2 GigabitEthernet
0/0/0
255.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0
[R4]dis isis lsdb
Database information for ISIS(15)
---------------------------------
Level-2 Link State Database
LSPID Seq Num Checksum Holdtime Length ATT/P/OL
-------------------------------------------------------------------------------
3333.3333.3333.00-00 0x00000009 0x838d 634 112 0/0/0
3333.3333.3333.02-00 0x00000001 0x985 495 55 0/0/0
4444.4444.4444.00-00* 0x00000004 0xf40d 497 70 0/0/0
4444.4444.4444.00-01* 0x00000001 0xef70 1143 41 0/0/0
Total LSP(s): 4
*(In TLV)-Leaking Route, *(By LSPID)-Self LSP, +-Self LSP(Extended),
ATT-Attached, P-Partition, OL-Overload
[R4]dis ip routing-table
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: Public
Destinations : 11 Routes : 11
Destination/Mask Proto Pre Cost Flags NextHop Interface
12.1.1.0/24 ISIS-L2 15 30 D 34.1.1.3 GigabitEthernet
0/0/0
23.1.1.0/24 ISIS-L2 15 20 D 34.1.1.3 GigabitEthernet
0/0/0
34.1.1.0/24 Direct 0 0 D 34.1.1.4 GigabitEthernet
0/0/0
34.1.1.4/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0
34.1.1.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet
0/0/0
44.44.44.44/32 Direct 0 0 D 127.0.0.1 LoopBack0
127.0.0.0/8 Direct 0 0 D 127.0.0.1 InLoopBack0
127.0.0.1/32 Direct 0 0 D 127.0.0.1 InLoopBack0
127.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0
222.222.222.222/32 ISIS-L2 15 84 D 34.1.1.3 GigabitEthernet
0/0/0
255.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0
路由渗透
将L2路由通过L1/L2路由器引入到L1区域。解决ISIS次优路径问题。
ATT、OL、down(用于防环) ppt，isis-name 需要成对配置
ISIS认证
接口等级
ISIS接口级别可以指定接口至发送哪个级别的IIH，这样可以节约资源
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