①IS指路由器
②ISIS属于大型内部网关路由协议类似OSPF,多用于运营商,企业网很少使用
③使用SPF算法,链路状态类路由协议
④ISIS封装数据包是基于OSI模型,OSPF、RIP、以及常见的以太网数据包封装都是基于TCP/IP模型
⑤ISIS划分区域是基于路由器。即一个路由器只能属于一个区域
⑥ISIS也是两层架构(骨干区域、常规区域)
ISIS路由器的种类:
①Level 1 路由器:仅收发L1的isis报文
②Level 2 路由器:仅收发L2的isis报文
③Level 1 2 路由器:可以收发L1和L2的isis报文
骨干区域
连续一片Level 2路由器(包含L 1 2)的集合
注意:
①默认情况下所有运行ISIS的路由器都是Level 1 2路由器
②L 1 2路由器类型OSPF中的ABR
L2路由器类似OSPF中骨干区域路由器
L1路由器类似OSPF中常规区域路由器

<Huawei>system-view     //进入系统视图
[Huawei]undo info-center enable     //关闭信息告警提示
[Huawei]sysname R1     // 改名
[R1]interface g0/0/0     //进入接口
[R1-GigabitEthernet0/0/0]ip address 12.1.1.1 24     //设置IP地址 
[R1-GigabitEthernet0/0/0]quit     //退出 
[R1]interface LoopBack 0     //进入环回接口 
[R1-LoopBack0]ip address 1.1.1.1 24     //设置IP地址 
[R1-LoopBack0]quit     //退出 
[R1]interface LoopBack 8     //进入环回接口 
[R1-LoopBack8]ip address 8.8.8.8 24     //设置IP地址 
[R1-LoopBack8]quit     //退出 
[R1]
<Huawei>system-view     //进入系统视图 
[Huawei]undo info-center enable      //关闭信息告警
[Huawei]sysname R2     //改名
[R2]interfac g0/0/0     //进入接口
[R2-GigabitEthernet0/0/0]ip address 12.1.1.2 24     //设置IP地址
[R2-GigabitEthernet0/0/0]quit     // 退出
[R2]interface LoopBack 0     // 进入环回接口
[R2-LoopBack0]ip address 2.2.2.2 24     //设置Ip地址
[R2-LoopBack0]quit     // 退出
[R2]interface g0/0/1     // 进入接口
[R2-GigabitEthernet0/0/1]ip address 23.1.1.2 24     // 设置IP地址
[R2-GigabitEthernet0/0/1]quit     // 退出
[R2]
<Huawei>system-view     //进入系统视图 
[Huawei]undo info-center enable     //  关闭信息告警提示
[Huawei]sysname R3     // 改名
[R3]interface g0/0/0     //进入接口 
[R3-GigabitEthernet0/0/0]ip address 23.1.1.3 24     // 设置IP地址
[R3-GigabitEthernet0/0/0]quit     // 退出
[R3]interface LoopBack 0     // 进入环回接口
[R3-LoopBack0]ip address 3.3.3.3 24     // 设置IP地址
[R3-LoopBack0]quit     // 退出
[R3]interface g0/0/1     // 进入接口
[R3-GigabitEthernet0/0/1]ip address 34.1.1.3 24     // 设置IP地址
[R3-GigabitEthernet0/0/1]quit     // 退出
[R3]
<Huawei>system-view     //进入系统视图 
[Huawei]undo info-center enable     // 关闭信息告警提示
[Huawei]sysname R4     // 改名
[R4]interface g0/0/0     // 进入接口
[R4-GigabitEthernet0/0/0]ip address 34.1.1.4 24     // 设置IP地址
[R4-GigabitEthernet0/0/0]quit     // 退出
[R4]interface LoopBack 0     // 进入环回接口
[R4-LoopBack0]ip address 4.4.4.4 24     // 设置IP地址
[R4-LoopBack0]quit     // 退出
[R4]interface g0/0/1     // 进入接口
[R4-GigabitEthernet0/0/1]ip address 45.1.1.4 24     // 设置IP地址
[R4-GigabitEthernet0/0/1]quit     // 退出
[R4]
<Huawei>system-view      //进入系统视图 
[Huawei]undo info-center enable     // 关闭信息告警提示
[Huawei]sysname R5     // 改名
[R5]interface g0/0/0     // 进入接口
[R5-GigabitEthernet0/0/0]ip address 45.1.1.5 24     //设置IP地址 
[R5-GigabitEthernet0/0/0]quit     // 退出
[R5]interface LoopBack 0     // 进入环回接口
[R5-LoopBack0]ip address 5.5.5.5 24     // 设置IP地址
[R5-LoopBack0]quit     // 退出
[R5]
配置网络实体标识,类似OSPF中的Router-ID,标识该中间系统(路由器)的身份信息。
其中49.0002表示路由器所在的区域
0000.0000.1111表示系统ID即Router-ID.00固定格式
[R1]isis     // 进入ISIS
[R1-isis-1]network-entity 49.0002.0000.0000.1111.00     //设置路由器所在区域和路由器ID
[R1-isis-1]quit     //退出 
[R1]
[R2]isis     //进入ISIS   
[R2-isis-1]network-entity 49.0002.0000.0000.2222.00     //设置路由器所在区域和路由器ID
[R2-isis-1]quit     //退出
[R2]
[R3]isis     //进入ISIS   
[R3-isis-1]network-entity 49.0001.0000.0000.3333.00     //设置路由器所在区域和路由器ID 
[R3-isis-1]quit     //退出 
[R3]
[R4]isis     //进入ISIS   
[R4-isis-1]network-entity 49.0003.0000.0000.4444.00     //设置路由器所在区域和路由器ID 
[R4-isis-1]quit     //退出 
[R4]
[R5]isis     //进入ISIS   
[R5-isis-1]network-entity 49.0003.0000.0000.5555.00     //设置路由器所在区域和路由器ID 
[R5-isis-1]quit     //退出 
[R5]
[R1]interface g0/0/0     //进入接口
[R1-GigabitEthernet0/0/0]isis enable 1     //宣告网段
[R1-GigabitEthernet0/0/0]quit     //退出
[R1]interface LoopBack 0     //进入环回接口   
[R1-LoopBack0]isis enable 1     //宣告网段
[R1-LoopBack0]quit     //退出
[R1]rip     //进入RIP
[R1-rip-1]version 2     //协议2
[R1-rip-1]undo summary     //关闭自动汇总
[R1-rip-1]network 8.0.0.0     //宣告网段
[R1-rip-1]quit     //退出
[R1]
[R2]interface g0/0/0     //进入接口
[R2-GigabitEthernet0/0/0]isis enable 1     //宣告网段
[R2-GigabitEthernet0/0/0]quit     //退出
[R2]interface g0/0/1     //进入接口
[R2-GigabitEthernet0/0/1]isis enable 1     //宣告网段
[R2-GigabitEthernet0/0/1]quit     //退出
[R2]interface LoopBack 0     //进入环回接口
[R2-LoopBack0]isis enable 1     //宣告网段
[R2-LoopBack0]quit     //退出
[R2]
[R3]interface g0/0/0     //进入接口
[R3-GigabitEthernet0/0/0]isis enable 1     //宣告网段
[R3-GigabitEthernet0/0/0]quit     //退出
[R3]interface g0/0/1     //进入接口
[R3-GigabitEthernet0/0/1]isis  enable 1     //宣告网段
[R3-GigabitEthernet0/0/1]quit     //退出
[R3]interface LoopBack 0     //进入换回接口
[R3-LoopBack0]isis enable 1     //宣告网段
[R3-LoopBack0]quit     //退出
[R3]
[R4]interface g0/0/0     //进入接口
[R4-GigabitEthernet0/0/0]isis enable 1     //宣告网段
[R4-GigabitEthernet0/0/0]quit     //退出
[R4]interface g0/0/1     //进入接口
[R4-GigabitEthernet0/0/1]isis enable 1     //宣告网段
[R4-GigabitEthernet0/0/1]quit     //退出
[R4]interface LoopBack 0     //进入环回接口
[R4-LoopBack0]isis enable 1     //宣告网段
[R4-LoopBack0]quit     //退出
[R4]
[R5]interface g0/0/0     //进入接口
[R5-GigabitEthernet0/0/0]isis enable 1     //宣告网段
[R5-GigabitEthernet0/0/0]quit     //退出
[R5]interface LoopBack 0     //进入环回接口   
[R5-LoopBack0]isis enable 1     //宣告网段
[R5-LoopBack0]quit     //退出
[R5]
[R3]dis ip routing-table      //查看路由表
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: Public
         Destinations : 19       Routes : 19       
Destination/Mask    Proto   Pre  Cost      Flags NextHop         Interface
        1.1.1.0/24  ISIS-L2 15   20          D   23.1.1.2        GigabitEthernet
0/0/0
        2.2.2.0/24  ISIS-L2 15   10          D   23.1.1.2        GigabitEthernet
0/0/0
        3.3.3.0/24  Direct  0    0           D   3.3.3.3         LoopBack0
        3.3.3.3/32  Direct  0    0           D   127.0.0.1       LoopBack0
      3.3.3.255/32  Direct  0    0           D   127.0.0.1       LoopBack0
        4.4.4.0/24  ISIS-L2 15   10          D   34.1.1.4        GigabitEthernet
0/0/1
        5.5.5.0/24  ISIS-L2 15   20          D   34.1.1.4        GigabitEthernet
0/0/1
       12.1.1.0/24  ISIS-L2 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
       45.1.1.0/24  ISIS-L2 15   20          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
255.255.255.255/32  Direct  0    0           D   127.0.0.1       InLoopBack0
[R3]
//除了RIP的路由,其他路由都学到了
默认情况下,骨干区域的路由不会发送到L1路由器(常规区域),且L1路由器会自动形成指向L12路由器的缺省路由(这种特性类似OSPF中的totally stub)
[R1]isis     //进入ISIS   
[R1-isis-1]is-level level-1     //修改路由器的类型为L1
[R1-isis-1]quit     //退出
[R1]
[R1]dis ip routing-table     //查看路由表    
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: Public
         Destinations : 16       Routes : 16       
Destination/Mask    Proto   Pre  Cost      Flags NextHop         Interface
        0.0.0.0/0   ISIS-L1 15   10          D   12.1.1.2        GigabitEthernet     //默认增加一条缺省路由
0/0/0
        1.1.1.0/24  Direct  0    0           D   1.1.1.1         LoopBack0
        1.1.1.1/32  Direct  0    0           D   127.0.0.1       LoopBack0
      1.1.1.255/32  Direct  0    0           D   127.0.0.1       LoopBack0
        2.2.2.0/24  ISIS-L1 15   10          D   12.1.1.2        GigabitEthernet
0/0/0
        8.8.8.0/24  Direct  0    0           D   8.8.8.8         LoopBack8
        8.8.8.8/32  Direct  0    0           D   127.0.0.1       LoopBack8
      8.8.8.255/32  Direct  0    0           D   127.0.0.1       LoopBack8
       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
      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
[R1]
[R3]isis     //进入ISIS   
[R3-isis-1]is-level level-2          // 修改路由器的类型为L2
[R3-isis-1]quit     // 退出
[R3]
[R5]isis     // 进入ISIS  
[R5-isis-1]is-level level-1     // 修改路由器的类型为L1
[R5-isis-1]quit     // 退出
[R5]
[R5]dis ip routing-table     // 查看路由表
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   45.1.1.4        GigabitEthernet          // 默认增加一条缺省路由
0/0/0
        4.4.4.0/24  ISIS-L1 15   10          D   45.1.1.4        GigabitEthernet
0/0/0
        5.5.5.0/24  Direct  0    0           D   5.5.5.5         LoopBack0
        5.5.5.5/32  Direct  0    0           D   127.0.0.1       LoopBack0
      5.5.5.255/32  Direct  0    0           D   127.0.0.1       LoopBack0
       34.1.1.0/24  ISIS-L1 15   20          D   45.1.1.4        GigabitEthernet
0/0/0
       45.1.1.0/24  Direct  0    0           D   45.1.1.5        GigabitEthernet
0/0/0
       45.1.1.5/32  Direct  0    0           D   127.0.0.1       GigabitEthernet
0/0/0
     45.1.1.255/32  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
[R5]
R1——查看ISIS简要信息
[R1]dis isis brief     //查看ISIS简要信息
                     ISIS Protocol Information for ISIS(1)
                     -------------------------------------
SystemId: 0000.0000.1111      System Level: L1     //类型为L1    
Area-Authentication-mode: NULL
Domain-Authentication-mode: NULL
Ipv6 is not enabled
ISIS is in invalid restart status
ISIS is in protocol hot standby state: Real-Time Backup
Interface: 12.1.1.1(GE0/0/0)
Cost: L1 10        L2 10                Ipv6 Cost: L1 10   L2 10   
State: IPV4 Up                          IPV6 Down
Type: BROADCAST                         MTU: 1497      
Priority: L1 64   L2 64   
Timers:     Csnp: L1 10    L2 10    ,Retransmit: L12 5   , Hello: L1 10 L2 10  ,
Hello Multiplier: L1 3    L2 3     , LSP-Throttle Timer: L12 50  
Interface: 1.1.1.1(Loop0)
Cost: L1 0         L2 0                 Ipv6 Cost: L1 0    L2 0    
State: IPV4 Up                          IPV6 Down
Type: P2P                               MTU: 1500      
Priority: L1 64   L2  64   
Timers:     Csnp: L12 10  , Retransmit: L12 5   , Hello: 10  ,
Hello Multiplier: 3            , LSP-Throttle Timer: L12 50  
[R1]
R3——查看ISIS简要信息
[R3]dis isis brief     //查看ISIS简要信息 
                     ISIS Protocol Information for ISIS(1)
                     -------------------------------------
SystemId: 0000.0000.3333      System Level: L2     //类型为L2    
Area-Authentication-mode: NULL
Domain-Authentication-mode: NULL
Ipv6 is not enabled
ISIS is in invalid restart status
ISIS is in protocol hot standby state: Real-Time Backup
Interface: 23.1.1.3(GE0/0/0)
Cost: L1 10        L2 10                Ipv6 Cost: L1 10   L2 10   
State: IPV4 Up                          IPV6 Down
Type: BROADCAST                         MTU: 1497      
Priority: L1 64   L2 64   
Timers:     Csnp: L1 10    L2 10    ,Retransmit: L12 5   , Hello: L1 10 L2 10  ,
Hello Multiplier: L1 3    L2 3     , LSP-Throttle Timer: L12 50  
Interface: 34.1.1.3(GE0/0/1)
Cost: L1 10        L2 10                Ipv6 Cost: L1 10   L2 10   
State: IPV4 Up                          IPV6 Down
Type: BROADCAST                         MTU: 1497      
Priority: L1 64   L2 64   
Timers:     Csnp: L1 10    L2 10    ,Retransmit: L12 5   , Hello: L1 10 L2 10  ,
Hello Multiplier: L1 3    L2 3     , LSP-Throttle Timer: L12 50  
Interface: 3.3.3.3(Loop0)
Cost: L1 0         L2 0                 Ipv6 Cost: L1 0    L2 0    
State: IPV4 Up                          IPV6 Down
Type: P2P                               MTU: 1500      
Priority: L1 64   L2  64   
Timers:     Csnp: L12 10  , Retransmit: L12 5   , Hello: 10  ,
Hello Multiplier: 3            , LSP-Throttle Timer: L12 50  
[R3]
[R5]dis isis brief     //查看ISIS简要信息
                     ISIS Protocol Information for ISIS(1)
                     -------------------------------------
SystemId: 0000.0000.5555      System Level: L1     //类型为L1    
Area-Authentication-mode: NULL
Domain-Authentication-mode: NULL
Ipv6 is not enabled
ISIS is in invalid restart status
ISIS is in protocol hot standby state: Real-Time Backup
Interface: 45.1.1.5(GE0/0/0)
Cost: L1 10        L2 10                Ipv6 Cost: L1 10   L2 10   
State: IPV4 Up                          IPV6 Down
Type: BROADCAST                         MTU: 1497      
Priority: L1 64   L2 64   
Timers:     Csnp: L1 10    L2 10    ,Retransmit: L12 5   , Hello: L1 10 L2 10  ,
Hello Multiplier: L1 3    L2 3     , LSP-Throttle Timer: L12 50  
Interface: 5.5.5.5(Loop0)
Cost: L1 0         L2 0                 Ipv6 Cost: L1 0    L2 0    
State: IPV4 Up                          IPV6 Down
Type: P2P                               MTU: 1500      
Priority: L1 64   L2  64   
Timers:     Csnp: L12 10  , Retransmit: L12 5   , Hello: 10  ,
Hello Multiplier: 3            , LSP-Throttle Timer: L12 50  
[R5]
[R2]interface g0/0/0     //进入接口
[R2-GigabitEthernet0/0/0]isis circuit-level level-1     //设置该接口只发送L1报文      
[R2-GigabitEthernet0/0/0]quit     //退出  
[R2]interface g0/0/1     //进入接口     
[R2-GigabitEthernet0/0/1]isis circuit-level level-2     //设置该接口只发送L2报文  
[R2-GigabitEthernet0/0/1]quit     //退出  
[R2]
<R1>ping 3.3.3.3     //测试是否可以ping 通R3设备
  PING 3.3.3.3: 56  data bytes, press CTRL_C to break
    Reply from 3.3.3.3: bytes=56 Sequence=1 ttl=254 time=50 ms
    Reply from 3.3.3.3: bytes=56 Sequence=2 ttl=254 time=20 ms
    Reply from 3.3.3.3: bytes=56 Sequence=3 ttl=254 time=20 ms
    Reply from 3.3.3.3: bytes=56 Sequence=4 ttl=254 time=20 ms
    Reply from 3.3.3.3: bytes=56 Sequence=5 ttl=254 time=30 ms     //ping 通
  --- 3.3.3.3 ping statistics ---
    5 packet(s) transmitted
    5 packet(s) received
    0.00% packet loss
    round-trip min/avg/max = 20/28/50 ms
<R1>
[R4]interface g0/0/0     //进入接口 
[R4-GigabitEthernet0/0/0]isis circuit-level level-2     //设置该接口只发送L2报文  
[R4-GigabitEthernet0/0/0]quit     //退出  
[R4]interface g0/0/1     //进入接口     
[R4-GigabitEthernet0/0/1]isis circuit-level level-1     //设置该接口只发送L1报文  
[R4-GigabitEthernet0/0/1]quit     //退出  
[R4]
<R5>ping 3.3.3.3     //测试是否可以ping 通R3设备 
  PING 3.3.3.3: 56  data bytes, press CTRL_C to break
    Reply from 3.3.3.3: bytes=56 Sequence=1 ttl=254 time=10 ms
    Reply from 3.3.3.3: bytes=56 Sequence=2 ttl=254 time=40 ms
    Reply from 3.3.3.3: bytes=56 Sequence=3 ttl=254 time=30 ms
    Reply from 3.3.3.3: bytes=56 Sequence=4 ttl=254 time=30 ms
    Reply from 3.3.3.3: bytes=56 Sequence=5 ttl=254 time=40 ms     //ping 通 
  --- 3.3.3.3 ping statistics ---
    5 packet(s) transmitted
    5 packet(s) received
    0.00% packet loss
    round-trip min/avg/max = 10/30/40 ms
<R5>
[R3]dis isis peer     //查看邻居表    
                          Peer information for ISIS(1)
  System Id     Interface          Circuit Id       State HoldTime Type     PRI
-------------------------------------------------------------------------------
0000.0000.2222  GE0/0/0            0000.0000.3333.01 Up   21s      L2       64 
0000.0000.4444  GE0/0/1            0000.0000.4444.01 Up   8s       L2       64 
Total Peer(s): 2
[R3]
[R3]dis isis lsdb     //查看拓扑表   
                        Database information for ISIS(1)
                        --------------------------------
                          Level-2 Link State Database
LSPID                 Seq Num      Checksum      Holdtime      Length  ATT/P/OL
-------------------------------------------------------------------------------
0000.0000.2222.00-00  0x0000001e   0xed40        1084          114     0/0/0   
0000.0000.3333.00-00* 0x0000000e   0x9ec3        1045          113     0/0/0   
0000.0000.3333.01-00* 0x00000006   0xf484        1045          55      0/0/0   
0000.0000.4444.00-00  0x00000017   0xc492        1153          114     0/0/0   
0000.0000.4444.01-00  0x00000005   0xb261        1153          55      0/0/0   
0000.0000.5555.00-00  0x0000000a   0x96c7        166           110     0/0/0   
Total LSP(s): 6
    *(In TLV)-Leaking Route, *(By LSPID)-Self LSP, +-Self LSP(Extended), 
           ATT-Attached, P-Partition, OL-Overload
[R3]
[R1]isis     //进入ISIS       
[R1-isis-1]import-route rip 1 level-1     //接level 1指的是以level 1的形式引入
[R1-isis-1]quit     //退出    
[R1]
[R3]dis ip routing-table     //查看路由表     
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: Public
         Destinations : 20       Routes : 20       
Destination/Mask    Proto   Pre  Cost      Flags NextHop         Interface
        1.1.1.0/24  ISIS-L2 15   20          D   23.1.1.2        GigabitEthernet
0/0/0
        2.2.2.0/24  ISIS-L2 15   10          D   23.1.1.2        GigabitEthernet
0/0/0
        3.3.3.0/24  Direct  0    0           D   3.3.3.3         LoopBack0
        3.3.3.3/32  Direct  0    0           D   127.0.0.1       LoopBack0
      3.3.3.255/32  Direct  0    0           D   127.0.0.1       LoopBack0
        4.4.4.0/24  ISIS-L2 15   10          D   34.1.1.4        GigabitEthernet
0/0/1
        5.5.5.0/24  ISIS-L2 15   20          D   34.1.1.4        GigabitEthernet
0/0/1
        8.8.8.0/24  ISIS-L2 15   84          D   23.1.1.2        GigabitEthernet     //RIP路由信息成功引入
0/0/0
       12.1.1.0/24  ISIS-L2 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
       45.1.1.0/24  ISIS-L2 15   20          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
255.255.255.255/32  Direct  0    0           D   127.0.0.1       InLoopBack0
[R3]原文:https://blog.51cto.com/13541307/2507816