Briefly describe IS-IS dynamic routing protocol
- Link state protocol, using SPF algorithm
- Use Hello packet to establish neighbor relationship, use LSP to exchange link state information, adopt hierarchical design
- There are two routing levels, L1 and L2.
L1 is responsible for spreading link state information in the same area (similar to type 1 and 2 in OSPF)
L2 is responsible for spreading link state information to each other in different areas (similar to OSPF Category 3) - Three kinds of routers: L1 can obtain the path information in the
area , L2 can obtain the path information between the areas,
L1-2: Can obtain the intra-area and inter-area paths at the same time - The path connecting the L2 router and the L1/L2 router will form a backbone area
- The IS-IS area boundary is located on the link, not in the router, each IS-IS router belongs to only one area
Neighbor relationship graph
Area1 --------L1-------Area1
R1(L1)------------------R2(L1)
Area1 -----None-------Area1
R1(L2)------------------R2(L1)
Area1 -------- L2 ------- Area1
R1 (L2) ------------------ R2 (L1-2)
Area1 ------None-----Area2
R1(L1)------------------R2(L1-2)
Area1 -------- L2 ------- Area2
R1 (L2) ------------------ R2 (L1-2)
Area1 --------L1L2-------Area2
R1(L1-2)----------------R2(L1-2)
NSAP address
1. The NSAP address is 8-20 bytes, identified in hexadecimal, and contains the following main information:
【1】Region number
[2] System number (fixed 6 bytes)
[3] NSEL bit (fixed 1 byte and set to 0)
For example: 49.0001.0002.0002.0002.00
2. Common planning methods for NET addresses in existing networks
It can be obtained by complementing the 32-bit address of the loopback port into 48 bits.
For example: 221.15.23.180 ### fills in 3 bits, then 4 bits are divided into
221.15.23.180 ------> 221.015.023.180 ------> 2210.1502 .3180
after conversion: 49.0020.2210.1502.3180.00
Zone 1
12.12.12.12 ------> 0120.1201.2012 ------> 49.0001.0120.1201.2012.00
Area 30
218.120.130.11 ------> 2181.2013.0011 ------> 49.0030.2181.2013.0011.00
IS-IS protocol configuration roadmap
- Start the IS-IS process and configure the NET address according to the regional plan
- Configure IS-IS routing type according to network structure
- Under the interface, announce the mouth to the IS-IS process
R1 placement
interface GigabitEthernet0/0/0 //设置接口
ip address 16.0.0.1 255.255.255.252
interface GigabitEthernet0/0/1
ip address 12.0.0.1 255.255.255.252
isis enable 1 //启动ISIS
interface LoopBack0 //创建环回口
ip address 1.1.1.1 255.255.255.255 //设置IP
isis enable 1
isis 1 //isis 后面跟进程。默认不加就是1进程
is-level level-1 //根据网络结构配置IS-IS路由类型，这边有路由器类型
network-entity 49.0001.0010.0100.1001.00 //设置NSAP地址
import-route rip 1 level-1 //引入后变成l1信息 默认值
summary 203.0.0.0 255.255.254.0 level-1 //域间路由汇总
rip 1
undo summary //取消汇总
version 2
network 16.0.0.0 //宣告网段
import-route isis 1 cost 5 //引入ISIS 1 路由条目 累加 cost 5 是花销
引路由
R2 configuration
interface GigabitEthernet0/0/0
ip address 23.0.0.1 255.255.255.252
isis enable 1
interface GigabitEthernet0/0/1
ip address 12.0.0.2 255.255.255.252
isis enable 1
interface LoopBack0
ip address 2.2.2.2 255.255.255.255
isis enable 1
isis 1
network-entity 49.0001.0020.0200.2002.00
import-route isis level-2 into level-1
R3 configuration
interface GigabitEthernet0/0/0
ip address 23.0.0.2 255.255.255.252
isis enable 1
interface GigabitEthernet0/0/1
ip address 34.0.0.1 255.255.255.252
isis enable 1
interface LoopBack0
ip address 3.3.3.3 255.255.255.255
isis enable 1
isis 1
is-level level-2
network-entity 49.0000.0030.0300.3003.00
R4 configuration
interface GigabitEthernet0/0/0
ip address 45.0.0.1 255.255.255.252
isis enable 1
interface GigabitEthernet0/0/1
ip address 34.0.0.2 255.255.255.252
isis enable 1
interface LoopBack0
ip address 4.4.4.4 255.255.255.255
isis enable 1
isis 1
network-entity 49.0002.0040.0400.4004.00
import-route isis level-2 into level-1
summary 202.0.0.0 255.255.254.0 level-1-2
R5 configuration
interface GigabitEthernet0/0/0
ip address 45.0.0.2 255.255.255.252
isis enable 1
isis cost 22
interface LoopBack0
ip address 5.5.5.5 255.255.255.255
isis enable 1
interface LoopBack1
ip address 202.0.0.1 255.255.255.0
isis enable 1
interface LoopBack2
ip address 202.0.1.1 255.255.255.0
isis enable 1
isis 1
is-level level-1
network-entity 49.0002.0050.0500.5005.00
R6 configuration
interface GigabitEthernet0/0/0
ip address 16.0.0.2 255.255.255.252
interface LoopBack0
ip address 6.6.6.6 255.255.255.255
interface LoopBack1
ip address 203.0.0.1 255.255.255.0
interface LoopBack2
ip address 203.0.1.1 255.255.255.0
rip 1
undo summary
version 2
network 16.0.0.0
network 6.0.0.0
network 203.0.0.0
network 203.0.1.0