Contents

Introduction· 1

Prerequisites· 1

Example: Configuring IS-IS route summarization· 1

Network configuration· 1

Analysis· 2

Applicable hardware and software versions· 2

Procedures· 4

Configuring IP addresses for interfaces· 4

Configuring basic IS-IS· 5

Configuring IS-IS route summarization· 6

Verifying the configuration· 6

Configuration files· 6

 

Introduction

This document provides IS-IS route summarization configuration examples.

Prerequisites

The configuration examples in this document 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.

This document assumes that you have basic knowledge of IS-IS route summarization.

Example: Configuring IS-IS route summarization

Network configuration

As shown in Figure 1, 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. Configure IS-IS route summarization to reduce routing entries and save system resources for Device B.

Figure 1 Network diagram

 

Table 1 Interface and IP address assignment

Device	Interface	IP address	Device	Interface	IP address
Device A	Vlan-int10	172.16.1.1/24	Device B	Vlan-int10	172.168.1.2/24
	Vlan-int101	10.1.1.1/24	GW 1	Vlan-int101	10.1.1.2/24
	Vlan-int102	10.1.2.1/24	GW 2	Vlan-int102	10.1.2.2/24
	Vlan-int103	10.1.3.1/24	GW3	Vlan-int103	10.1.3.2/24

 

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 192.168.0.0/22.

Applicable hardware and software versions

The following matrix shows the hardware and software versions to which this configuration example is applicable:

 

Hardware	Software version
S6812 switch series S6813 switch series	Release 6615Pxx, Release 6628Pxx
S6550XE-HI switch series	Release 6008 and later, Release 8106Pxx
S6525XE-HI switch series	Release 6008 and later, Release 8106Pxx
S5850 switch series	Release 8005 and later
S5570S-EI switch series	Release 11xx
S5560X-EI switch series	Release 63xx, Release 65xx, Release 6615Pxx, Release 6628Pxx
S5560X-HI switch series	Release 63xx, Release 65xx, Release 6615Pxx, Release 6628Pxx
S5500V2-EI switch series	Release 63xx, Release 65xx, Release 6615Pxx, Release 6628Pxx
MS4520V2-30F switch	Release 63xx, Release 65xx, Release 6615Pxx, Release 6628Pxx
MS4520V2-30C switch MS4520V2-54C switch	Release 65xx, Release 6615Pxx, Release 6628Pxx
MS4520V2-28S switch MS4520V2-24TP switch	Release 63xx
S6520X-HI switch series S6520X-EI switch series	Release 63xx, Release 65xx, Release 6615Pxx, Release 6628Pxx
S6520X-SI switch series S6520-SI switch series	Release 63xx, Release 65xx, Release 6615Pxx, Release 6628Pxx
S5000-EI switch series	Release 63xx, Release 65xx, Release 6615Pxx, Release 6628Pxx
MS4600 switch series	Release 63xx, Release 65xx, Release 6615Pxx, Release 6628Pxx
ES5500 switch series	Release 63xx, Release 65xx, Release 6615Pxx, Release 6628Pxx
S5560S-EI switch series S5560S-SI switch series	Release 63xx
S5500V3-24P-SI S5500V3-48P-SI	Release 63xx
S5500V3-SI switch series (except S5500V3-24P-SI and S5500V3-48P-SI)	Release 11xx
S5170-EI switch series	Not supported
S5130S-HI switch series S5130S-EI switch series S5130S-SI switch series S5130S-LI switch series	Not supported
S5120V2-SI switch series S5120V2-LI switch series	Not supported
S5120V3-EI switch series	Not supported
S5120V3-36F-SI S5120V3-28P-HPWR-SI S5120V3-54P-PWR-SI	Not supported
S5120V3-SI switch series (except S5120V3-36F-SI, S5120V3-28P-HPWR-SI, and S5120V3-54P-PWR-SI)	Not supported
S5120V3-LI switch series	Not supported
S3600V3-EI switch series	Release 11xx
S3600V3-SI switch series	Not supported
S3100V3-EI switch series S3100V3-SI switch series	Not supported
S5110V2 switch series	Not supported
S5110V2-SI switch series	Not supported
S5000V3-EI switch series S5000V5-EI switch series	Not supported
S5000E-X switch series S5000X-EI switch series	Not supported
E128C switch E152C switch E500C switch series E500D switch series	Not supported
MS4320V2 switch series MS4320V3 switch series MS4300V2 switch series MS4320 switch series MS4200 switch series	Not supported
WS5850-WiNet switch series	Release 63xx
WS5820-WiNet switch series WS5810-WiNet switch series	Not supported
WAS6000 switch series	Not supported
IE4300-12P-AC switch IE4300-12P-PWR switch IE4300-M switch series IE4320 switch series	Not supported

 

Procedures

Configuring IP addresses for interfaces

# Configure an IP address for the interface VLAN-interface 10 on Device A.

<DeviceA> system-view

[DeviceA] interface vlan-interface 10

[DeviceA-Vlan-interface10] ip address 172.16.1.1 24

[DeviceA-Vlan-interface10] quit

# Configure IP addresses for other interfaces as shown in Figure 1 in the same way VLAN-interface 10 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 the interface VLAN-interface 10.

[DeviceA] interface vlan-interface 10

[DeviceA–Vlan-interface10] isis enable 1

[DeviceA–Vlan-interface10] quit

# Configure other interfaces in the same way VLAN-interface 10 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 the interface VLAN-interface 10.

[DeviceB] interface vlan-interface 10

[DeviceB–Vlan-interface10] isis enable 1

[DeviceB–Vlan-interface10] 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 the interface VLAN-interface 11.

[GW1] interface vlan-interface 11

[GW1–Vlan-interface11] isis enable 1

[GW1–Vlan-interface11] 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    Vlan10          172.16.1.1      R/-/-

 10.1.1.0/24          20         NULL    Vlan10          172.16.1.1      R/-/-

 192.168.2.0/24       30         NULL    Vlan10          172.16.1.1      R/-/-

 10.1.2.0/24          20         NULL    Vlan10          172.16.1.1      R/-/-

 192.168.3.0/24       30         NULL    Vlan10          172.16.1.1      R/-/-

 10.1.3.0/24          20         NULL    Vlan10          172.16.1.1      R/-/-

 172.16.1.0/24        10         NULL    Vlan10          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] address-family ipv4

[DeviceA-isis-1-ipv4]summary 192.168.0.0 22

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    Vlan10          172.16.1.1      R/-/-

 10.1.2.0/24          20         NULL    Vlan10          172.16.1.1      R/-/-

 10.1.3.0/24          20         NULL    Vlan10          172.16.1.1      R/-/-

 172.16.1.0/24        10         NULL    Vlan10          Direct          D/L/-

 192.168.0.0/22       30         NULL    Vlan10          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 192.168.0.0/22.

Configuration files

·     Device A:

#

isis 1

 network-entity 10.0000.0000.0001.00

 #

 address-family ipv4 unicast

  summary 192.168.0.0 255.255.252.0

#

vlan 10

#

vlan 101 to 103

#

interface vlan-interface10

 ip address 172.16.1.1 255.255.255.0

 isis enable 1

#

interface vlan-interface101

 ip address 10.1.1.1 255.255.255.0

 isis enable 1

#

interface vlan-interface102

 ip address 10.1.2.1 255.255.255.0

 isis enable 1

#

interface vlan-interface103

 ip address 10.1.3.1 255.255.255.0

 isis enable 1

#

·     Device B:

#

isis 1

 is-level level-2

 network-entity 10.0000.0000.0002.00

#

vlan 10

#

interface vlan-interface10

 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

#

vlan 11

#

vlan 101

#

interface vlan-interface101

 ip address 10.1.1.2 255.255.255.0

 isis enable 1

#

interface vlan-interface11

 ip address 192.168.1.1 255.255.255.0

 isis enable 1

#

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