H3C Routers

IS-IS Configuration Examples

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Contents

Introduction· 1

Prerequisites· 1

Example: Configuring IS-IS·· 1

Network configuration· 1

Analysis· 2

Software versions used· 2

Restrictions and guidelines· 2

Procedures· 3

Configuring Router A· 3

Configuring Router B· 3

Configuring Router C· 3

Configuring Router D·· 4

Configuring Router E· 5

Verifying the configuration· 5

Configuration files· 8

Router A· 8

Router B· 8

Router C· 8

Router D·· 9

Router E· 9

Example: Configuring IS-IS route summarization· 10

Network configuration· 10

Analysis· 10

Software versions used· 11

Procedures· 11

Configuring IP addresses for interfaces· 11

Configuring basic IS-IS· 11

Configuring IS-IS route summarization· 12

Verifying the configuration· 12

Configuration files· 13

Device A· 13

Device B· 14

GW 1· 14

Other gateways· 14

Related documentation· 15

 

Introduction

This document provides IS-IS configuration examples.

Prerequisites

The following information applies to Comware 9-based routers. Procedures and information in the examples might be slightly different depending on the software or hardware version of the routers.

The configuration examples were created and verified in a lab environment, and all the devices were started with the factory default configuration. When you are working on a live network, make sure you understand the potential impact of every command on your network.

The following information is provided based on the assumption that you have basic knowledge of IS-IS.

Example: Configuring IS-IS

Network configuration

As shown in Figure 1, the company's headquarters and the branch run IS-IS. The partner runs OSPF.

Configure the routers to meet the following requirements:

·     The Marketing department can reach the F&A department, the branch, and the partner.

·     The F&A department and the branch cannot reach each other, and the branch does not have a route to the F&A department.

·     When the IS-IS process on Router C restarts, the communication is not interrupted.

Figure 1 Network diagram

‌

Analysis

To meet the network requirements, you must perform the following tasks:

·     To reduce traffic for Router A and Router B, configure them as Level-1 routers to allow communication only between the Marketing department and the F&A department.

·     Configure Router C to use a prefix list to advertise only network 10.100.1.0/24 to Level-2 to ensure that the branch does not have a route to the F&A department.

·     Configure route redistribution between IS-IS and OSPF on Router D to allow communication between the Marketing department and the partner.

·     Enable IS-IS Graceful Restart (GR) on Router C to ensure that the communication is not interrupted when the IS-IS process on Router C restarts.

Software versions used

This configuration example was created and verified on R9141P16 of the MSR2630E-X1 device.

Restrictions and guidelines

To avoid blackhole routes, do not change the network topology during the IS-IS GR process.

Procedures

Configuring Router A

# Configure an IP address for GigabitEthernet 1/0/1.

<RouterA> system-view

[RouterA] interface gigabitethernet 1/0/1

[RouterA-GigabitEthernet1/0/1] ip address 192.168.1.1 24

[RouterA-GigabitEthernet1/0/1] quit

# Configure IP addresses for other interfaces, as shown in Figure 1. (Details not shown.)

# Configure IS-IS.

[RouterA] isis 1

[RouterA-isis-1] is-level level-1

[RouterA-isis-1] network-entity 10.1921.6800.1001.00

[RouterA-isis-1] quit

[RouterA] interface gigabitethernet 1/0/1

[RouterA–GigabitEthernet1/0/1] isis enable 1

[RouterA–GigabitEthernet1/0/1] quit

[RouterA] interface gigabitethernet 1/0/2

[RouterA–GigabitEthernet1/0/2] isis enable 1

[RouterA–GigabitEthernet1/0/2] quit

Configuring Router B

# Configure an IP address for GigabitEthernet 1/0/1.

<RouterB> system-view

[RouterB] interface gigabitethernet 1/0/1

[RouterB-GigabitEthernet1/0/1] ip address 192.168.2.1 24

[RouterB-GigabitEthernet1/0/1] quit

# Configure IP addresses for other interfaces, as shown in Figure 1. (Details not shown.)

# Configure IS-IS.

[RouterB] isis 1

[RouterB-isis-1] is-level level-1

[RouterB-isis-1] network-entity 10.1921.6800.2001.00

[RouterB-isis-1] quit

[RouterB] interface gigabitethernet 1/0/1

[RouterB–GigabitEthernet1/0/1] isis enable 1

[RouterB–GigabitEthernet1/0/1] quit

[RouterB] interface gigabitethernet 1/0/2

[RouterB–GigabitEthernet1/0/2] isis enable 1

[RouterB–GigabitEthernet1/0/2] quit

Configuring Router C

# Configure an IP address for GigabitEthernet 1/0/1.

<RouterC> system-view

[RouterC] interface gigabitethernet 1/0/1

[RouterC-GigabitEthernet1/0/1] ip address 192.168.1.2 24

[RouterC-GigabitEthernet1/0/1] quit

# Configure IP addresses for other interfaces, as shown in Figure 1. (Details not shown.)

# Configure IS-IS.

[RouterC] isis 1

[RouterC-isis-1] network-entity 10.1921.6801.0001.00

[RouterC-isis-1] quit

[RouterC] interface gigabitethernet 1/0/1

[RouterC–GigabitEthernet1/0/1] isis enable 1

[RouterC–GigabitEthernet1/0/1] quit

[RouterC] interface gigabitethernet 1/0/2

[RouterC–GigabitEthernet1/0/2] isis enable 1

[RouterC–GigabitEthernet1/0/2] quit

[RouterC] interface gigabitethernet 1/0/3

[RouterC–GigabitEthernet1/0/3] isis enable 1

[RouterC–GigabitEthernet1/0/3] quit

# Configure route leaking from Level-1 to Level-2, and use prefix list 1 to advertise only network 10.100.1.0/24 to Level-2.

[RouterC] ip prefix-list 1 permit 10.100.1.0 24

[RouterC] isis 1

[RouterC-isis-1] address-family ipv4

[RouterC-isis-1-ipv4] import-route isis level-1 into level-2 filter-policy prefix-list 1

[RouterC-isis-1-ipv4] quit

# Enable IS-IS GR.

[RouterC -isis-1] graceful-restart

[RouterC -isis-1] quit

Configuring Router D

# Configure an IP address for GigabitEthernet 1/0/1.

<RouterD> system-view

[RouterD] interface gigabitethernet 1/0/1

[RouterD-GigabitEthernet1/0/1] ip address 192.168.10.2 24

[RouterD-GigabitEthernet1/0/1] quit

# Configure IP addresses for other interfaces, as shown in Figure 1. (Details not shown.)

# Configure IS-IS.

[RouterD] isis 1

[RouterD-isis-1] is-level level-2

[RouterD-isis-1] network-entity 20.1921.6802.0001.00

[RouterD-isis-1] quit

[RouterD] interface gigabitethernet 1/0/1

[RouterD–GigabitEthernet1/0/1] isis enable 1

[RouterD–GigabitEthernet1/0/1] quit

[RouterD] interface gigabitethernet 1/0/2

[RouterD–GigabitEthernet1/0/2] isis enable 1

[RouterD–GigabitEthernet1/0/2] quit

# Configure OSPF.

[RouterD] ospf

[RouterD-ospf-1] area 0

[RouterD-ospf-1-area-0.0.0.0] network 192.168.20.0 0.0.0.255

[RouterD-ospf-1-area-0.0.0.0] quit

[RouterD-ospf-1] quit

# Redistribute OSPF and direct routes into IS-IS.

[RouterD] isis 1

[RouterD-isis-1] address-family ipv4

[RouterD-isis-1-ipv4] import-route ospf

[RouterD-isis-1-ipv4] import-route direct

[RouterD-isis-1-ipv4] quit

[RouterD-isis-1] quit

# Redistribute IS-IS and direct routes into OSPF.

[RouterD] ospf 1

[RouterD-ospf-1] import-route isis 1

[RouterD-ospf-1] import-route direct

Configuring Router E

# Configure an IP address for GigabitEthernet 1/0/1.

<RouterE> system-view

[RouterE] interface gigabitethernet 1/0/1

[RouterE-GigabitEthernet1/0/1] ip address 192.168.20.2 24

[RouterE-GigabitEthernet1/0/1] quit

# Configure IP addresses for other interfaces, as shown in Figure 1. (Details not shown.)

# Configure OSPF.

[RouterE] ospf

[RouterE-ospf-1] area 0

[RouterE-ospf-1-area-0.0.0.0] network 192.168.20.0 0.0.0.255

[RouterE-ospf-1-area-0.0.0.0] network 10.200.1.0 0.0.0.255

[RouterE-ospf-1-area-0.0.0.0] quit

[RouterE-ospf-1] quit

Verifying the configuration

# View the IS-IS routing table on Router D and verify that the branch can reach the Marketing department, but cannot reach the F&A department.

[RouterD] display isis route

 

                         Route information for IS-IS(1)

                         ------------------------------

 

                         Level-2 IPv4 Forwarding Table

                         -----------------------------

 

 IPv4 Destination     IntCost    ExtCost ExitInterface   NextHop         Flags

-------------------------------------------------------------------------------

 192.168.10.0/24      10         NULL    GE1/0/1         Direct          D/L/-

 192.168.1.0/24       20         NULL    GE1/0/1         192.168.10.1    R/-/-

 10.100.1.0/24        30         NULL    GE1/0/1         192.168.10.1    R/-/-

 192.168.2.0/24       20         NULL    GE1/0/1         192.168.10.1    R/-/-

 192.168.20.0/24      10         NULL    GE1/0/2         Direct          D/L/-

 

      Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set

# Verify that the company can communicate with the partner.

·     Display the IS-IS routing table on Router C.

[RouterC] display isis route

 

                         Route information for IS-IS(1)

                         ------------------------------

 

                         Level-1 IPv4 Forwarding Table

                         -----------------------------

 

 IPv4 Destination     IntCost    ExtCost ExitInterface   NextHop         Flags

-------------------------------------------------------------------------------

 192.168.10.0/24      10         NULL    GE1/0/3         Direct          D/L/-

 192.168.1.0/24       10         NULL    GE1/0/1         Direct          D/L/-

 10.100.1.0/24        20         NULL    GE1/0/1         192.168.1.1     R/L/-

 10.100.2.0/24        20         NULL    GE1/0/2         192.168.2.1     R/-/-

 192.168.2.0/24       10         NULL    GE1/0/2         Direct          D/L/-

 

      Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set

 

                         Level-2 IPv4 Forwarding Table

                         -----------------------------

 

 IPv4 Destination     IntCost    ExtCost ExitInterface   NextHop         Flags

-------------------------------------------------------------------------------

 192.168.10.0/24      10         NULL    GE1/0/3         Direct          D/L/-

 10.200.1.0/24        10         0       GE1/0/3         192.168.10.2    R/-/-

 192.168.20.0/24      10         0       GE1/0/3         192.168.10.2    R/-/-

 192.168.1.0/24       10         NULL    GE1/0/1         Direct          D/L/-

 192.168.2.0/24       10         NULL    GE1/0/2         Direct          D/L/-

 

      Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set

·     Ping 10.200.1.1 from Router C.

[RouterC] ping 10.200.1.1

Ping 10.200.1.1 (10.200.1.1): 56 data bytes, press CTRL_C to break

56 bytes from 10.200.1.1: icmp_seq=0 ttl=254 time=1.862 ms

56 bytes from 10.200.1.1: icmp_seq=1 ttl=254 time=2.969 ms

56 bytes from 10.200.1.1: icmp_seq=2 ttl=254 time=1.402 ms

56 bytes from 10.200.1.1: icmp_seq=3 ttl=254 time=1.324 ms

56 bytes from 10.200.1.1: icmp_seq=4 ttl=254 time=1.510 ms

 

--- Ping statistics for 10.200.1.1 ---

5 packet(s) transmitted, 5 packet(s) received, 0.0% packet loss

round-trip min/avg/max/std-dev = 1.324/1.813/2.969/0.606 ms

# Verify that the communication is not interrupted when the IS-IS process restarts.

·     Ping Router B from Router A.

[RouterA] ping -c 10000 10.100.2.1

Ping 10.100.2.1 (10.100.2.1): 56 data bytes, press CTRL_C to break

56 bytes from 10.100.2.1: icmp_seq=0 ttl=254 time=1.185 ms

56 bytes from 10.100.2.1: icmp_seq=1 ttl=254 time=1.087 ms

……

·     Restart the IS-IS process on Router C.

[RouterC] quit

<RouterC> reset isis all graceful-restart

Reset IS-IS process? [Y/N] :y

# Ping Router B from Router A and verify that the communication is not interrupted when the IS-IS process restarts.

[RouterA] ping -c 10000 10.100.2.1

Ping 10.100.2.1 (10.100.2.1): 56 data bytes, press CTRL_C to break

56 bytes from 10.100.2.1: icmp_seq=0 ttl=254 time=1.185 ms

56 bytes from 10.100.2.1: icmp_seq=1 ttl=254 time=1.087 ms

56 bytes from 13.13.13.3: icmp_seq=2 ttl=254 time=1.672 ms

56 bytes from 13.13.13.3: icmp_seq=3 ttl=254 time=1.751 ms

56 bytes from 13.13.13.3: icmp_seq=4 ttl=254 time=1.816 ms

56 bytes from 13.13.13.3: icmp_seq=5 ttl=254 time=1.814 ms

# Check the IS-IS GR state on Router C.

<RouterC> display isis graceful-restart status

 

                        Restart information for IS-IS(1)

                        --------------------------------

Restart status: COMPLETE

Restart phase: Finish

Restart t1: 3, count 10; Restart t2: 60; Restart t3: 300

SA Bit: supported

 

                          Level-1 restart information

                          ---------------------------

Total number of interfaces: 3

Number of waiting LSPs: 0

 

                          Level-2 restart information

                          ---------------------------

Total number of interfaces: 3

Number of waiting LSPs: 0

Configuration files

Router A

#

isis 1

 is-level level-1

 network-entity 10.1921.6800.1001.00

#

interface GigabitEthernet1/0/1

 ip address 192.168.1.1 255.255.255.0

 isis enable 1

#

interface GigabitEthernet1/0/2

 ip address 10.100.1.1 255.255.255.0

 isis enable 1

#

Router B

#

isis 1

 is-level level-1

 network-entity 10.1921.6800.2001.00

#

interface GigabitEthernet1/0/1

 ip address 192.168.2.1 255.255.255.0

 isis enable 1

#

interface GigabitEthernet1/0/2

 ip address 10.100.2.1 255.255.255.0

 isis enable 1

#

Router C

#

isis 1

 graceful-restart

 network-entity 10.1921.6801.0001.00

 #

 address-family ipv4 unicast

  import-route isis level-1 into level-2 filter-policy prefix-list 1

#

interface GigabitEthernet1/0/1

 ip address 192.168.1.2 255.255.255.0

 isis enable 1

#

interface GigabitEthernet1/0/2

 ip address 192.168.2.2 255.255.255.0

 isis enable 1

#

interface GigabitEthernet1/0/3

 ip address 192.168.10.1 255.255.255.0

 isis enable 1

#

 ip prefix-list 1 index 10 permit 10.100.1.0 24

#

Router D

#

isis 1

 is-level level-2

 network-entity 20.1921.6802.0001.00

#

 address-family ipv4 unicast

  import-route direct

  import-route ospf 1

#

ospf 1

 import-route direct

 import-route isis 1

 area 0.0.0.0

  network 192.168.20.0 0.0.0.255

#

interface GigabitEthernet1/0/1

 ip address 192.168.10.2 255.255.255.0

 isis enable 1

#

interface GigabitEthernet1/0/2

 ip address 192.168.20.1 255.255.255.0

#

Router E

#

ospf 1

 area 0.0.0.0

  network 10.200.1.0 0.0.0.255

  network 192.168.20.0 0.0.0.255

#

interface GigabitEthernet1/0/1

 ip address 192.168.20.2 255.255.255.0

#

interface GigabitEthernet1/0/2

 ip address 10.200.1.1 255.255.255.0

#

Example: Configuring IS-IS route summarization

Network configuration

As shown in Figure 2, the five departments of a company use IS-IS to connect to the backbone network. The five departments are assigned the networks 192.168.1.0/24, 192.168.2.0/24, 192.168.3.0/24, 192.168.4.0/24, and 192.168.5.0/24, respectively. Configure IS-IS route summarization to reduce routing entries and save system resources for Device B.

Figure 2 Network diagram

‌

Analysis

Configure route summarization on Device A, because route summarization applies only to locally generated LSPs.

To avoid blackhole routes, set the summary route to 192.168.0.0/21.

Software versions used

This configuration example was created and verified on R9141P16 of the MSR2630E-X1 device.

Procedures

Configuring IP addresses for interfaces

# Configure an IP address for GigabitEthernet 1/0/6 on Device A.

<DeviceA> system-view

[DeviceA] interface gigabitethernet 1/0/6

[DeviceA-GigabitEthernet1/0/6] ip address 172.16.1.1 24

[DeviceA-GigabitEthernet1/0/6] quit

# Configure IP addresses for other interfaces as shown in Figure 2 in the same way GigabitEthernet 1/0/6 is configured. (Details not shown.)

Configuring basic IS-IS

Configuring Device A

# Enable IS-IS on Device A and configure Device A as a Level-1-2 router.

[DeviceA] isis 1

[DeviceA-isis-1] network-entity 10.0000.0000.0001.00

[DeviceA-isis-1] is-level level-1-2

[DeviceA-isis-1] quit

# Enable IS-IS on GigabitEthernet 1/0/1.

[DeviceA] interface gigabitethernet 1/0/1

[DeviceA–GigabitEthernet1/0/1] isis enable 1

[DeviceA–GigabitEthernet1/0/1] quit

# Configure other interfaces in the same way GigabitEthernet 1/0/1 is configured. (Details not shown.)

Configuring Device B

# Enable IS-IS on Device B and configure Device B as a Level-2 router.

[DeviceB] isis 1

[DeviceB-isis-1] network-entity 10.0000.0000.0002.00

[DeviceB-isis-1] is-level level-2

[DeviceB-isis-1] quit

# Enable IS-IS on GigabitEthernet 1/0/1.

[DeviceB] interface gigabitethernet 1/0/1

[DeviceB–GigabitEthernet1/0/1] isis enable 1

[DeviceB–GigabitEthernet1/0/1] quit

Configuring the gateways

# Enable IS-IS on GW 1 and configure GW 1 as a Level-1 router.

[GW1] isis 1

[GW1-isis-1] network-entity 10.0001.0001.0001.00

[GW1-isis-1] is-level level-1

[GW1-isis-1] quit

# Enable IS-IS on GigabitEthernet 1/0/1.

[GW1] interface gigabitethernet 1/0/1

[GW1–GigabitEthernet1/0/1] isis enable 1

[GW1–GigabitEthernet1/0/1] quit

# Configure other gateways in the same way GW 1 is configured. (Details not shown.)

Displaying IS-IS routing information on Device B

# Display IS-IS routing information on Device B to view the network address of each department.

[DeviceB] display isis route

 

Route information for IS-IS(1)

                         ------------------------------

 

                         Level-2 IPv4 Forwarding Table

                         -----------------------------

 

 IPv4 Destination     IntCost    ExtCost ExitInterface   NextHop         Flags

-------------------------------------------------------------------------------

 192.168.1.0/24       30         NULL    GE1/0/1         172.16.1.1      R/-/-

 10.1.1.0/24          20         NULL    GE1/0/1         172.16.1.1      R/-/-

 192.168.2.0/24       30         NULL    GE1/0/1         172.16.1.1      R/-/-

 10.1.2.0/24          20         NULL    GE1/0/1         172.16.1.1      R/-/-

 192.168.3.0/24       30         NULL    GE1/0/1         172.16.1.1      R/-/-

 10.1.3.0/24          20         NULL    GE1/0/1         172.16.1.1      R/-/-

 192.168.4.0/24       30         NULL    GE1/0/1         172.16.1.1      R/-/-

 10.1.4.0/24          20         NULL    GE1/0/1         172.16.1.1      R/-/-

 192.168.5.0/24       30         NULL    GE1/0/1         172.16.1.1      R/-/-

 10.1.5.0/24          20         NULL    GE1/0/1         172.16.1.1      R/-/-

 172.16.1.0/24        10         NULL    GE1/0/1         Direct          D/L/-

 

      Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set

Configuring IS-IS route summarization

# Configure IS-IS route summarization on Device A.

[DeviceA] isis 1

[DeviceA-isis-1] address-family ipv4

[DeviceA-isis-1-ipv4] summary 192.168.0.0 21

Verifying the configuration

# Display IS-IS routing information on Device B.

[DeviceB] display isis route

 

                         Route information for IS-IS(1)

                         ------------------------------

 

                         Level-2 IPv4 Forwarding Table

                         -----------------------------

 

 IPv4 Destination     IntCost    ExtCost ExitInterface   NextHop         Flags

-------------------------------------------------------------------------------

 10.1.1.0/24          20         NULL    GE1/0/1         172.16.1.1      R/-/-

 10.1.2.0/24          20         NULL    GE1/0/1         172.16.1.1      R/-/-

 10.1.3.0/24          20         NULL    GE1/0/1         172.16.1.1      R/-/-

 10.1.4.0/24          20         NULL    GE1/0/1         172.16.1.1      R/-/-

 10.1.5.0/24          20         NULL    GE1/0/1         172.16.1.1      R/-/-

 172.16.1.0/24        10         NULL    GE1/0/1         Direct          D/L/-

 192.168.0.0/21       30         NULL    GE1/0/1         172.16.1.1      R/-/-

 

      Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set

The output shows that the networks have been summarized into a single network 192.168.0.0/21.

Configuration files

Device A

#

isis 1

 network-entity 10.0000.0000.0001.00

 #

 address-family ipv4

 summary 192.168.0.0 255.255.248.0

#

interface GigabitEthernet1/0/1

 port link-mode route

 ip address 10.1.1.1 255.255.255.0

 isis enable 1

#

interface GigabitEthernet1/0/2

 port link-mode route

 ip address 10.1.2.1 255.255.255.0

 isis enable 1

#

interface GigabitEthernet1/0/3

 port link-mode route

 ip address 10.1.3.1 255.255.255.0

 isis enable 1

#

interface GigabitEthernet1/0/4

 port link-mode route

 ip address 10.1.4.1 255.255.255.0

 isis enable 1

#

interface GigabitEthernet1/0/5

 port link-mode route

 ip address 10.1.5.1 255.255.255.0

 isis enable 1

#

interface GigabitEthernet1/0/7

 port link-mode route

 ip address 172.16.1.1 255.255.255.0

 isis enable 1

#

Device B

#

isis 1

 is-level level-2

 network-entity 10.0000.0000.0002.00

#

interface GigabitEthernet1/0/1

 port link-mode route

 ip address 172.16.1.2 255.255.255.0

 isis enable 1

#

GW 1

#

isis 1

 is-level level-1

 network-entity 10.0001.0001.0001.00

#

interface GigabitEthernet1/0/1

 port link-mode route

 ip address 10.1.1.2 255.255.255.0

 isis enable 1

#

interface GigabitEthernet1/0/2

 port link-mode route

 ip address 192.168.1.1 255.255.255.0

 isis enable 1

#

Other gateways

The configuration files for other gateways are similar to the configuration file for GW 1. (Details not shown.)

Related documentation

·     Layer 3—IP Routing Configuration Guide in H3C MSR1000[2600][3600] Routers Configuration Guides(V9)

·     Layer 3—IP Routing Command Reference in H3C MSR1000[2600][3600] Routers Command References(V9)