2.15 Examples for Configuring of ISIS
2.15.3 Example for Configuring IS-IS DIS Election
interface GigabitEthernet1/0/0 ip address 172.1.4.1 255.255.255.0 isis enable 1
#
interface GigabitEthernet2/0/0 ip address 172.1.1.1 255.255.255.0 isis enable 1
#
interface GigabitEthernet3/0/0 ip address 172.1.2.1 255.255.255.0 isis enable 1
#
interface GigabitEthernet4/0/0 ip address 172.1.3.1 255.255.255.0 isis enable 1
# return
2.15.3 Example for Configuring IS-IS DIS Election
Networking Requirements
As shown in Figure 2-15-3, four routers on the broadcast network communicate using IS-IS. RouterA and RouterB are Level-1-2 routers, RouterC is a Level-1 router, and RouterD is a Level-2 router.
RouterA with high performance needs to be configured as a Level-2 DIS.
2016-1-11 Huawei Confidential Page 72 of 1210 Figure 2-15-3 Networking diagram of configuring IS-IS DIS election
Configuration Roadmap
The configuration roadmap is as follows:
1. Configure IS-IS to enable network interconnectivity.
2. Configure the DIS priority of RouterA to 100 so that RouterA can be elected as a Level-2 DIS.
Procedure
1. Configure IP addresses for interfaces on each router.
# Configure RouterA.
[RouterA] interface gigabitethernet 1/0/0
[RouterA-GigabitEthernet1/0/0] ip address 10.1.1.1 24
The configurations of RouterB, RouterC, and RouterD are similar to the configuration of RouterA, and are not mentioned here.
2. View the MAC address of the GE interface on each router.
# View the MAC address of GigabitEthernet1/0/0 on RouterA.
[RouterA] display arp interface gigabitethernet 1/0/0
IP ADDRESS MAC ADDRESS EXPIRE(M) TYPE INTERFACE VPN-INSTANCE
VLAN/CEVLAN PVC ---
10.1.1.1 00e0-fc10-afec I - GE1/0/0 --- Total:1 Dynamic:0 Static:0 Interface:1
# View the MAC address of GigabitEthernet1/0/0 on RouterB.
[RouterB] display arp interface gigabitethernet 1/0/0
IP ADDRESS MAC ADDRESS EXPIRE(M) TYPE INTERFACE VPN-INSTANCE
VLAN/CEVLAN PVC ---
10.1.1.2 00e0-fccd-acdf I - GE1/0/0 --- Total:1 Dynamic:0 Static:0 Interface:1
# View the MAC address of GigabitEthernet1/0/0 on RouterC.
[RouterC] display arp interface gigabitethernet 1/0/0
IP ADDRESS MAC ADDRESS EXPIRE(M) TYPE INTERFACE VPN-INSTANCE
VLAN/CEVLAN PVC ---
10.1.1.3 00e0-fc50-25fe I - GE1/0/0 --- Total:1 Dynamic:0 Static:0 Interface:1
# View the MAC address of GigabitEthernet1/0/0 on RouterD.
[RouterD] display arp interface gigabitethernet 1/0/0
IP ADDRESS MAC ADDRESS EXPIRE(M) TYPE INTERFACE VPN-INSTANCE
VLAN/CEVLAN PVC ---
10.1.1.4 00e0-fcfd-305c I - GE1/0/0 --- Total:1 Dynamic:0 Static:0 Interface:1 3. Enable IS-IS
# Configure RouterA.
[RouterA] isis 1
[RouterA-isis-1] network-entity 10.0000.0000.0001.00 [RouterA-isis-1] quit
[RouterA] interface gigabitethernet 1/0/0 [RouterA-GigabitEthernet1/0/0] isis enable 1 [RouterA-GigabitEthernet1/0/0] quit
# Configure RouterB.
[RouterB] isis 1
[RouterB-isis-1] network-entity 10.0000.0000.0002.00
2016-1-11 Huawei Confidential Page 74 of 1210 [RouterB-isis-1] quit
[RouterB] interface gigabitethernet 1/0/0 [RouterB-GigabitEthernet1/0/0] isis enable 1 [RouterB-GigabitEthernet1/0/0] quit
# Configure RouterC.
[RouterC] isis 1
[RouterC-isis-1] network-entity 10.0000.0000.0003.00 [RouterC-isis-1] is-level level-1
[RouterC-isis-1] quit
[RouterC] interface gigabitethernet 1/0/0 [RouterC-GigabitEthernet1/0/0] isis enable 1 [RouterC-GigabitEthernet1/0/0] quit
# Configure RouterD.
[RouterD] isis 1
[RouterD-isis-1] network-entity 10.0000.0000.0004.00 [RouterD-isis-1] is-level level-2
[RouterD-isis-1] quit
[RouterD] interface gigabitethernet 1/0/0 [RouterD-GigabitEthernet1/0/0] isis enable 1 [RouterD-GigabitEthernet1/0/0] quit
# View IS-IS neighbor information on RouterA.
[RouterA] display isis peer
Peer information for ISIS(1) ---
System Id Interface Circuit Id State HoldTime Type PRI ---
0000.0000.0002 GE1/0/0 0000.0000.0002.01 Up 9s L1(L1L2) 64 0000.0000.0003 GE1/0/0 0000.0000.0002.01 Up 27s L1 64 0000.0000.0002 GE1/0/0 0000.0000.0004.01 Up 28s L2(L1L2) 64 0000.0000.0004 GE1/0/0 0000.0000.0004.01 Up 8s L2 64
Total Peer(s): 4
# View IS-IS interface information on RouterA.
[RouterA] display isis interface
Interface information for ISIS(1) ---
Interface Id IPV4.State IPV6.State MTU Type DIS
GE1/0/0 001 Up Down 1497 L1/L2 No/No
# View IS-IS interface information on RouterB.
[RouterB] display isis interface
Interface information for ISIS(1) ---
Interface Id IPV4.State IPV6.State MTU Type DIS GE1/0/0 001 Up Down 1497 L1/L2 Yes/No
# View IS-IS interface information on RouterD.
[RouterD] display isis interface
Interface information for ISIS(1) ---
Interface Id IPV4.State IPV6.State MTU Type DIS GE1/0/0 001 Up Down 1497 L1/L2 No/Yes
NOTE:
As shown in the preceding interface information, when the default DIS priority is used, the IS-IS interface on RouterB has the largest MAC address among all the interfaces on the Level-1 routers. Therefore, RouterB is elected as the Level-1 DIS. The IS-IS interface on RouterD has the largest MAC address among all the interfaces on Level-2 routers. Therefore, RouterD is elected as the Level-2 DIS. Level-1 and Level-2 pseudonodes are 0000.0000.0002.01 and 0000.0000.0004.01 respectively.
4. Set the DIS priority of RouterA.
[RouterA] interface gigabitethernet 1/0/0
[RouterA-GigabitEthernet1/0/0] isis dis-priority 100
# View IS-IS neighbor information on RouterA.
[RouterA] display isis peer
Peer information for ISIS(1) ---
System Id Interface Circuit Id State HoldTime Type PRI ---
0000.0000.0002 GE1/0/0 0000.0000.0001.01 Up 21s L1(L1L2) 64 0000.0000.0003 GE1/0/0 0000.0000.0001.01 Up 27s L1 64 0000.0000.0002 GE1/0/0 0000.0000.0001.01 Up 28s L2(L1L2) 64 0000.0000.0004 GE1/0/0 0000.0000.0001.01 Up 30s L2 64
Total Peer(s): 4
2016-1-11 Huawei Confidential Page 76 of 1210 5. Verify the configuration.
# View IS-IS interface information on RouterA.
[RouterA] display isis interface
Interface information for ISIS(1) ---
Interface Id IPV4.State IPV6.State MTU Type DIS GE1/0/0 001 Up Down 1497 L1/L2 Yes/Yes
NOTE:
As shown in the preceding information, after the DIS priority of the IS-IS interface is changed, RouterA becomes a Level-1-2 DIS (DR) immediately and its pseudonode is 0000.0000.0001.01.
# View IS-IS neighbor and interface information on RouterB.
[RouterB] display isis peer
Peer information for ISIS(1) ---
System Id Interface Circuit Id State HoldTime Type PRI ---
0000.0000.0001 GE1/0/0 0000.0000.0001.01 Up 7s L1(L1L2) 100 0000.0000.0003 GE1/0/0 0000.0000.0001.01 Up 25s L1 64 0000.0000.0001 GE1/0/0 0000.0000.0001.01 Up 7s L2(L1L2) 100 0000.0000.0004 GE1/0/0 0000.0000.0001.01 Up 25s L2 64
Total Peer(s): 4
[RouterB] display isis interface
Interface information for ISIS(1) ---
Interface Id IPV4.State IPV6.State MTU Type DIS GE1/0/0 001 Up Down 1497 L1/L2 No/No
# View IS-IS neighbor and interface information on RouterD.
[RouterD] display isis peer
Peer information for ISIS(1) ---
System Id Interface Circuit Id State HoldTime Type PRI ---
0000.0000.0001 GE1/0/0 0000.0000.0001.01 Up 9s L2 100 0000.0000.0002 GE1/0/0 0000.0000.0001.01 Up 28s L2 64
Total Peer(s): 2
[RouterD] display isis interface
Interface information for ISIS(1) ---
Interface Id IPV4.State IPV6.State MTU Type DIS GE1/0/0 001 Up Down 1497 L1/L2 No/No
Configuration Files
Configuration file of RouterA
#
sysname RouterA
# isis 1
network-entity 10.0000.0000.0001.00
#
interface GigabitEthernet1/0/0 ip address 10.1.1.1 255.255.255.0 isis enable 1
isis dis-priority 100
# return
Configuration file of RouterB
#
sysname RouterB
# isis 1
network-entity 10.0000.0000.0002.00
#
interface GigabitEthernet1/0/0 ip address 10.1.1.2 255.255.255.0 isis enable 1
# return
Configuration file of RouterC
#
2016-1-11 Huawei Confidential Page 78 of 1210 sysname RouterC
# isis 1
is-level level-1
network-entity 10.0000.0000.0003.00
#
interface GigabitEthernet1/0/0 ip address 10.1.1.3 255.255.255.0 isis enable 1
# return
Configuration file of RouterD
#
sysname RouterD
# isis 1
is-level level-2
network-entity 10.0000.0000.0004.00
#
interface GigabitEthernet1/0/0 ip address 10.1.1.4 255.255.255.0 isis enable 1
# return