目标

介绍IS-IS DIS选举的配置过程,包括在各设备上配置IS-IS的基本功能和DIS优先级。

组网需求

路由器DeviceA、DeviceB、DeviceC和DeviceD都运行IS-IS路由协议以实现互连。

路由器DeviceA、DeviceB、DeviceC和DeviceD属于同一区域10,网络类型为广播网(以太网)。

DeviceA和DeviceB是Level-1-2设备,DeviceC是Level-1设备,DeviceD是Level-2设备。

DeviceA的DIS优先级为100。

要求通过改变接口的DIS优先级,将DeviceA配置为Level-1-2的DIS设备(DR)。

enspospf设置优先级 ensp配置优先级_IP

配置思路

  • 在各路由器上使能IS-IS,指定网络实体,实现互连。
  • 缺省优先级情况下,查看各路由器IS-IS接口的信息。
  • 配置路由器的DIS优先级。

操作步骤

  1. 配置各接口的IPv4地址(略)
  2. 查看各路由器上GE接口的MAC地址。当各接口的DIS优先级相同时,拥有MAC地址大的接口的路由器将被选择为DIS。

查看DeviceA上接口GigabitEthernet1/0/0的MAC地址。

[~DeviceA]dis arp int ethe 1/0/0
ARP timeout:1200s
IP ADDRESS      MAC ADDRESS     EXPIRE(M) TYPE        INTERFACE   VPN-INSTANCE
                                          VLAN/CEVLAN PVC
----------------------------------------------------------------------------------------
10.1.1.1        3860-aa01-0100            I -         Eth1/0/0         
----------------------------------------------------------------------------------------
Total:1         Dynamic:0       Static:0    Interface:1    Remote:0
Redirect:0
[~DeviceA]

查看DeviceB上接口GigabitEthernet1/0/0的MAC地址。

[~DeviceB]dis arp int ethe 1/0/0
ARP timeout:1200s
IP ADDRESS      MAC ADDRESS     EXPIRE(M) TYPE        INTERFACE   VPN-INSTANCE
                                          VLAN/CEVLAN PVC
----------------------------------------------------------------------------------------
10.1.1.2        3860-aa02-0100            I -         Eth1/0/0         
----------------------------------------------------------------------------------------
Total:1         Dynamic:0       Static:0    Interface:1    Remote:0
Redirect:0
[~DeviceB]

查看DeviceC上接口GigabitEthernet1/0/0的MAC地址。

[~DeviceC]dis arp int ethe 1/0/0
ARP timeout:1200s
IP ADDRESS      MAC ADDRESS     EXPIRE(M) TYPE        INTERFACE   VPN-INSTANCE
                                          VLAN/CEVLAN PVC
----------------------------------------------------------------------------------------
10.1.1.3        3860-aa03-0100            I -         Eth1/0/0         
----------------------------------------------------------------------------------------
Total:1         Dynamic:0       Static:0    Interface:1    Remote:0
Redirect:0
[~DeviceC]

查看DeviceD上接口GigabitEthernet1/0/0的MAC地址。

[~DeviceD]dis arp int ethe 1/0/0
ARP timeout:1200s
IP ADDRESS      MAC ADDRESS     EXPIRE(M) TYPE        INTERFACE   VPN-INSTANCE
                                          VLAN/CEVLAN PVC
----------------------------------------------------------------------------------------
10.1.1.4        3860-aa04-0100            I -         Eth1/0/0         
----------------------------------------------------------------------------------------
Total:1         Dynamic:0       Static:0    Interface:1    Remote:0
Redirect:0
[~DeviceD]
  1. 启动IS-IS

配置DeviceA。

DeviceA:
isis 1
 network-entity 10.0000.0000.0001.00
interface Ethernet1/0/0
 isis enable 1

配置DeviceB。

DeviceB:
isis 1
 network-entity 10.0000.0000.0002.00
interface Ethernet1/0/0
 isis enable 1

配置DeviceC。

DeviceC:
isis 1
 is-level level-1
 network-entity 10.0000.0000.0003.00
interface Ethernet1/0/0
 isis enable 1

配置DeviceD。

DeviceD:
isis 1
 is-level level-2
 network-entity 10.0000.0000.0004.00
interface Ethernet1/0/0
 isis enable 1

查看DeviceA的IS-IS邻居信息。

[~DeviceA-Ethernet1/0/0]dis isis peer      
                          Peer information for ISIS(1)
                         
  System Id     Interface          Circuit Id        State HoldTime Type     PRI
--------------------------------------------------------------------------------
0000.0000.0002  Eth1/0/0           0000.0000.0003.01  Up   30s      L1(L1L2) 64 
0000.0000.0003  Eth1/0/0           0000.0000.0003.01  Up   9s       L1       64 
0000.0000.0002  Eth1/0/0           0000.0000.0004.01  Up   31s      L2(L1L2) 64 
0000.0000.0004  Eth1/0/0           0000.0000.0004.01  Up   29s      L2       64 
Total Peer(s): 4
[~DeviceA-Ethernet1/0/0]

显示DeviceA的IS-IS接口信息。

[~DeviceA-Ethernet1/0/0]dis isis interface 
                       Interface information for ISIS(1)
                       ---------------------------------
 Interface         Id      IPV4.State          IPV6.State      MTU  Type  DIS
 Eth1/0/0          001         Up          Mtu:Dn/Lnk:Dn/IP:Dn 1497 L1/L2 No/No
[~DeviceA-Ethernet1/0/0]

显示DeviceB的IS-IS接口信息。

[~DeviceB-Ethernet1/0/0] dis isis interface 
                       Interface information for ISIS(1)
                       ---------------------------------
 Interface         Id      IPV4.State          IPV6.State      MTU  Type  DIS
 Eth1/0/0          001         Up          Mtu:Dn/Lnk:Dn/IP:Dn 1497 L1/L2 No/No
[~DeviceB-Ethernet1/0/0]

显示DeviceC的IS-IS接口信息。

[~DeviceC-Ethernet1/0/0]dis isis int 
                       Interface information for ISIS(1)
                       ---------------------------------
 Interface         Id      IPV4.State          IPV6.State      MTU  Type  DIS
 Eth1/0/0          001         Up          Mtu:Dn/Lnk:Dn/IP:Dn 1497 L1/L2 Yes/No
[~DeviceC-Ethernet1/0/0]

显示DeviceD的IS-IS接口信息。

[~DeviceD-Ethernet1/0/0]dis isis inter
                       Interface information for ISIS(1)
                       ---------------------------------
 Interface         Id      IPV4.State          IPV6.State      MTU  Type  DIS
 Eth1/0/0          001         Up          Mtu:Dn/Lnk:Dn/IP:Dn 1497 L1/L2 No/Yes
[~DeviceD-Ethernet1/0/0]

从接口信息中可以看到,在使用缺省DIS优先级的情况下,在Level-1级别的设备中,DeviceC上接口的MAC地址最大,因此DeviceC为Level-1的DIS;在Level-2级别的设备中,DeviceD上接口的MAC地址最大,因此DeviceD为Level-2的DIS。Level-1和Level-2的伪节点分别是0000.0000.0002.01和0000.0000.0004.01。

  1. 配置DeviceA的DIS优先级
DeviceA:
interface Ethernet1/0/0
 isis dis-priority 100

查看DeviceA的IS-IS邻居信息。

[~DeviceA-Ethernet1/0/0]dis isis peer
                          Peer information for ISIS(1)
                         
  System Id     Interface          Circuit Id        State HoldTime Type     PRI
--------------------------------------------------------------------------------
0000.0000.0002  Eth1/0/0           0000.0000.0001.01  Up   24s      L1(L1L2) 64 
0000.0000.0003  Eth1/0/0           0000.0000.0001.01  Up   24s      L1       64 
0000.0000.0002  Eth1/0/0           0000.0000.0001.01  Up   24s      L2(L1L2) 64 
0000.0000.0004  Eth1/0/0           0000.0000.0001.01  Up   24s      L2       64 
Total Peer(s): 4
[~DeviceA-Ethernet1/0/0]
  1. 验证配置结果

查看DeviceA的IS-IS接口信息。

[~DeviceA-Ethernet1/0/0]dis isis inter
                       Interface information for ISIS(1)
                       ---------------------------------
 Interface         Id      IPV4.State          IPV6.State      MTU  Type  DIS
 Eth1/0/0          001         Up          Mtu:Dn/Lnk:Dn/IP:Dn 1497 L1/L2 Yes/Yes
[~DeviceA-Ethernet1/0/0]

从上述信息中可以看到,在改变IS-IS接口的DIS优先级后,DeviceA立即成为Level-1-2的DIS(DR),且伪节点是0000.0000.0001.01。

显示DeviceB的IS-IS邻居和接口信息。

[~DeviceB-Ethernet1/0/0]dis isis peer
                          Peer information for ISIS(1)
                         
  System Id     Interface          Circuit Id        State HoldTime Type     PRI
--------------------------------------------------------------------------------
0000.0000.0001  Eth1/0/0           0000.0000.0001.01  Up   10s      L1(L1L2) 100
0000.0000.0003  Eth1/0/0           0000.0000.0001.01  Up   31s      L1       64 
0000.0000.0001  Eth1/0/0           0000.0000.0001.01  Up   10s      L2(L1L2) 100
0000.0000.0004  Eth1/0/0           0000.0000.0001.01  Up   28s      L2       64 
Total Peer(s): 4
[~DeviceB-Ethernet1/0/0]
[~DeviceB-Ethernet1/0/0]dis isis inter
                       Interface information for ISIS(1)
                       ---------------------------------
 Interface         Id      IPV4.State          IPV6.State      MTU  Type  DIS
 Eth1/0/0          001         Up          Mtu:Dn/Lnk:Dn/IP:Dn 1497 L1/L2 No/No
[~DeviceB-Ethernet1/0/0]

显示DeviceD的IS-IS邻居和接口信息。

[~DeviceD-Ethernet1/0/0]dis isis peer
                          Peer information for ISIS(1)
                         
  System Id     Interface          Circuit Id        State HoldTime Type     PRI
--------------------------------------------------------------------------------
0000.0000.0001  Eth1/0/0           0000.0000.0001.01  Up   9s       L2       100
0000.0000.0002  Eth1/0/0           0000.0000.0001.01  Up   23s      L2       64 
Total Peer(s): 2
[~DeviceD-Ethernet1/0/0] 
[~DeviceD-Ethernet1/0/0]dis isis inter
                       Interface information for ISIS(1)
                       ---------------------------------
 Interface         Id      IPV4.State          IPV6.State      MTU  Type  DIS
 Eth1/0/0          001         Up          Mtu:Dn/Lnk:Dn/IP:Dn 1497 L1/L2 No/No
[~DeviceD-Ethernet1/0/0]
[~DeviceD-Ethernet1/0/0]