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play_arrow Overview
- play_arrow Introduction to IS-IS
play_arrow Configuring IS-IS
play_arrow Monitoring and Troubleshooting Network Issues
- play_arrow Monitoring Networks
- play_arrow Troubleshooting Network Issues
- play_arrow Troubleshooting IS-IS
play_arrow Configuration Statements and Operational Commands
- Junos CLI Reference Overview

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English

Example: Redistributing OSPF Routes into IS-IS

date_range 18-Feb-21

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This example shows how to redistribute OSPF routes into an IS-IS network.

Requirements

No special configuration beyond device initialization is required before configuring this example.

Overview

Export policy can be applied to IS-IS to facilitate route redistribution.

Junos OS does not support the application of import policy for link-state routing protocols like IS-IS because such policies can lead to inconsistent link-state database (LSDB) entries, which in turn can result in routing inconstancies.

In this example, OSPF routes 192.168.0/24 through 192.168.3/24 are redistributed into IS-IS area 49.0002 from Device R2.

In addition, policies are configured to ensure that Device R1 can reach destinations on the 10.0.0.44/30 network, and that Device R3 can reach destinations on the 10.0.0.36/30 network. This enables end-to-end reachability.

Figure 1 shows the topology used in this example.

Figure 1: IS-IS Route Redistribution Topology

CLI Quick Configuration shows the configuration for all of the devices in Figure 1. The section #configuration759__isis-redist-ospf-step-by-step-r2 describes the steps on Device R2. #configuration759__isis-redist-ospf-step-by-step-r3 describes the steps on Device R3.

Topology

Configuration

CLI Quick Configuration

To quickly configure this example, copy the following commands, paste them into a text file, remove any line breaks, change any details necessary to match your network configuration, and then copy and paste the commands into the CLI at the [edit] hierarchy level.

Device R1

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set interfaces fe-1/2/0 unit 0 description to-R7
set interfaces fe-1/2/0 unit 0 family inet address 10.0.0.38/30
set interfaces fe-1/2/0 unit 0 family iso
set interfaces lo0 unit 0 family inet address 172.16.3.5/32
set interfaces lo0 unit 0 family iso address 49.0002.0172.0016.0305.00
set protocols isis interface fe-1/2/0.0
set protocols isis interface lo0.0

Device R2

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set interfaces fe-1/2/1 unit 0 description to-R5
set interfaces fe-1/2/1 unit 0 family inet address 10.0.0.37/30
set interfaces fe-1/2/1 unit 0 family iso
set interfaces fe-1/2/0 unit 0 description to-OSPF-network
set interfaces fe-1/2/0 unit 0 family inet address 10.0.0.45/30
set interfaces lo0 unit 0 family inet address 172.16.9.7/32
set interfaces lo0 unit 0 family iso address 49.0002.0172.0016.0907.00
set protocols isis export ospf-isis
set protocols isis export send-direct-to-isis-neighbors
set protocols isis interface fe-1/2/1.0
set protocols isis interface lo0.0
set protocols ospf export send-direct-to-ospf-neighbors
set protocols ospf area 0.0.0.1 interface fe-1/2/0.0
set protocols ospf area 0.0.0.1 interface lo0.0 passive
set policy-options policy-statement ospf-isis term 1 from protocol ospf
set policy-options policy-statement ospf-isis term 1 from route-filter 192.168.0.0/22 longer
set policy-options policy-statement ospf-isis term 1 then accept
set policy-options policy-statement send-direct-to-isis-neighbors from protocol direct
set policy-options policy-statement send-direct-to-isis-neighbors from route-filter 10.0.0.44/30 exact
set policy-options policy-statement send-direct-to-isis-neighbors then accept
set policy-options policy-statement send-direct-to-ospf-neighbors from protocol direct
set policy-options policy-statement send-direct-to-ospf-neighbors from route-filter 10.0.0.36/30 exact
set policy-options policy-statement send-direct-to-ospf-neighbors then accept

Device R3

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set interfaces fe-1/2/0 unit 0 family inet address 10.0.0.46/30
set interfaces lo0 unit 0 family inet address 192.168.1.1/32
set interfaces lo0 unit 0 family inet address 192.168.2.1/32
set interfaces lo0 unit 0 family inet address 192.168.3.1/32
set interfaces lo0 unit 0 family inet address 192.168.0.1/32
set protocols ospf export ospf
set protocols ospf area 0.0.0.1 interface fe-1/2/0.0
set protocols ospf area 0.0.0.1 interface lo0.0 passive
set policy-options policy-statement ospf term 1 from protocol static
set policy-options policy-statement ospf term 1 then accept
set routing-options static route 192.168.0.0/24 discard
set routing-options static route 192.168.1.0/24 discard
set routing-options static route 192.168.3.0/24 discard
set routing-options static route 192.168.2.0/24 discard

Step-by-Step Procedure

To configure Device R2:

Configure the network interfaces.

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[edit interfaces]
user@R2# set fe-1/2/1 unit 0 description to-R5
user@R2# set fe-1/2/1 unit 0 family inet address 10.0.0.37/30
user@R2# set fe-1/2/1 unit 0 family iso
user@R2# set fe-1/2/0 unit 0 description to-OSPF-network
user@R2# set fe-1/2/0 unit 0 family inet address 10.0.0.45/30
user@R2# set lo0 unit 0 family inet address 172.16.9.7/32
user@R2# set lo0 unit 0 family iso address 49.0002.0172.0016.0907.00

Configure IS-IS on the interface facing Device R1 and the loopback interface.
```
[edit protocols isis]
user@R2# set interface fe-1/2/1.0
user@R2# set interface lo0.0
```

Configure the policy that enables Device R1 to reach the 10.0.0.44/30 network.

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[edit policy-options policy-statement send-direct-to-isis-neighbors]
user@R2# set from protocol direct
user@R2# set from route-filter 10.0.0.44/30 exact
user@R2# set then accept

Apply the policy that enables Device R1 to reach the 10.0.0.44/30 network.
```
[edit protocols isis]
user@R2# set export send-direct-to-isis-neighbors
```

Configure OSPF on the interfaces.

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[edit protocols ospf]
user@R2# set area 0.0.0.1 interface fe-1/2/0.0
user@R2# set area 0.0.0.1 interface lo0.0 passive

Configure the OSPF route redistribution policy.

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[edit policy-options policy-statement ospf-isis term 1]
user@R2# set from protocol ospf
user@R2# set from route-filter 192.168.0.0/22 longer
user@R2# set then accept

Apply the OSPF route redistribution policy to the IS-IS instance.
```
[edit protocols isis]
user@R2# set export ospf-isis
```

Configure the policy that enables Device R3 to reach the 10.0.0.36/30 network.

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[edit policy-options policy-statement send-direct-to-ospf-neighbors]
user@R2# set from protocol direct
user@R2# set from route-filter 10.0.0.36/30 exact
user@R2# set then accept

Apply the policy that enables Device R3 to reach the 10.0.0.36/30 network.
```
[edit protocols ospf]
user@R2# set export send-direct-to-ospf-neighbors
```

Step-by-Step Procedure

The following example requires you to navigate various levels in the configuration hierarchy. For information about navigating the CLI, see Using the CLI Editor in Configuration Mode in the CLI User Guide.

To configure multi-level IS-IS:

Configure the network interfaces.

Multiple addresses are configured on the loopback interface to simulate multiple route destinations.

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[edit interfaces]
user@R3# set fe-1/2/0 unit 0 family inet address 10.0.0.46/30
user@R3# set lo0 unit 0 family inet address 192.168.1.1/32
user@R3# set lo0 unit 0 family inet address 192.168.2.1/32
user@R3# set lo0 unit 0 family inet address 192.168.3.1/32
user@R3# set lo0 unit 0 family inet address 192.168.0.1/32

Configure static routes to the loopback interface addresses.

These are the routes that are redistributed into IS-IS.

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[edit routing-options static]
user@R3# set route 192.168.0.0/24 discard
user@R3# set route 192.168.1.0/24 discard
user@R3# set route 192.168.3.0/24 discard
user@R3# set route 192.168.2.0/24 discard

Configure OSPF on the interfaces.

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[edit protocols ospf area 0.0.0.1]
user@R3# set interface fe-1/2/0.0
user@R3# set interface lo0.0 passive

Configure the OSPF policy to export the static routes.

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[edit policy-options policy-statement ospf term 1]
user@R3# set from protocol static
user@R3# set then accept

Apply the OSPF export policy.
```
[edit protocols ospf]
user@R3# set export ospf
```

Results

From configuration mode, confirm your configuration by entering the show interfaces, show protocols, show policy-options, and show routing-options commands. If the output does not display the intended configuration, repeat the instructions in this example to correct the configuration.

Device R2

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user@R2# show interfaces
fe-1/2/1 {
    unit 0 {
        description to-R5;
        family inet {
            address 10.0.0.37/30;
        }
        family iso;
    }
}
fe-1/2/0 {
    unit 0 {
        description to-OSPF-network;
        family inet {
            address 10.0.0.45/30;
        }
    }
}
lo0 {
    unit 0 {
        family inet {
            address 172.16.9.7/32;
        }
        family iso {
            address 49.0002.0172.0016.0907.00;
        }
    }
}

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user@R2# show protocols
isis {
    export [ ospf-isis send-direct-to-isis-neighbors ];
    interface fe-1/2/1.0;
    interface lo0.0;
}
ospf {
    export send-direct-to-ospf-neighbors;
    area 0.0.0.1 {
        interface fe-1/2/0.0;
        interface lo0.0 {
            passive;
        }
    }
}

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user@R2# show policy-options
policy-statement ospf-isis {
    term 1 {
        from {
            protocol ospf;
            route-filter 192.168.0.0/22 longer;
        }
        then accept;
    }
}
policy-statement send-direct-to-isis-neighbors {
    from {
        protocol direct;
        route-filter 10.0.0.44/30 exact;
    }
    then accept;
}
policy-statement send-direct-to-ospf-neighbors {
    from {
        protocol direct;
        route-filter 10.0.0.36/30 exact;
    }
    then accept;
}

Device R3

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user@R3# show interfaces
fe-1/2/0 {
    unit 0 {
        family inet {
            address 10.0.0.46/30;
        }
    }
}
lo0 {
    unit 0 {
        family inet {
            address 192.168.1.1/32;
            address 192.168.2.1/32;
            address 192.168.3.1/32;
            address 192.168.0.1/32;
        }
    }
}

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user@R3# show protocols
ospf {
    export ospf;
    area 0.0.0.1 {
        interface fe-1/2/0.0;
        interface lo0.0 {
            passive;
        }
    }
}

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user@R3# show policy-options
policy-statement ospf {
    term 1 {
        from protocol static;
        then accept;
    }
}

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user@R3# show routing-options
static {
    route 192.168.0.0/24 discard;
    route 192.168.1.0/24 discard;
    route 192.168.3.0/24 discard;
    route 192.168.2.0/24 discard;
}

If you are done configuring the device, enter commit from configuration mode.

Verification

Confirm that the configuration is working properly.

Verifying OSPF Route Advertisement
Verifying Route Redistribution
Verifying Connectivity

Verifying OSPF Route Advertisement

Purpose
Action
Meaning

Purpose

Make sure that the expected routes are advertised by OSPF.

Action

From operational mode on Device R2, enter the show route protocol ospf command.

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user@R2> show route protocol ospf


inet.0: 15 destinations, 15 routes (15 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both

192.168.0.0/24     *[OSPF/150] 03:54:21, metric 0, tag 0
                    > to 10.0.0.46 via fe-1/2/0.0
192.168.0.1/32     *[OSPF/10] 03:54:21, metric 1
                    > to 10.0.0.46 via fe-1/2/0.0
192.168.1.0/24     *[OSPF/150] 03:54:21, metric 0, tag 0
                    > to 10.0.0.46 via fe-1/2/0.0
192.168.1.1/32     *[OSPF/10] 03:54:21, metric 1
                    > to 10.0.0.46 via fe-1/2/0.0
192.168.2.0/24     *[OSPF/150] 03:54:21, metric 0, tag 0
                    > to 10.0.0.46 via fe-1/2/0.0
192.168.2.1/32     *[OSPF/10] 03:54:21, metric 1
                    > to 10.0.0.46 via fe-1/2/0.0
192.168.3.0/24     *[OSPF/150] 03:54:21, metric 0, tag 0
                    > to 10.0.0.46 via fe-1/2/0.0
192.168.3.1/32     *[OSPF/10] 03:54:21, metric 1
                    > to 10.0.0.46 via fe-1/2/0.0
224.0.0.5/32       *[OSPF/10] 03:56:03, metric 1
                         MultiRecv

iso.0: 1 destinations, 1 routes (1 active, 0 holddown, 0 hidden)

Meaning

The 192.168/16 routes are advertised by OSPF.

Verifying Route Redistribution

Purpose
Action
Meaning

Purpose

Make sure that the expected routes are redistributed from OSPF into IS-IS.

Action

From operational mode on Device R1, enter the show route protocol isis command.

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user@R1> show route protocol isis


inet.0: 13 destinations, 13 routes (13 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both

10.0.0.44/30       *[IS-IS/160] 03:45:24, metric 20
                    > to 10.0.0.37 via fe-1/2/0.0
172.16.9.7/32      *[IS-IS/15] 03:49:46, metric 10
                    > to 10.0.0.37 via fe-1/2/0.0
192.168.0.0/24     *[IS-IS/160] 03:49:46, metric 10
                    > to 10.0.0.37 via fe-1/2/0.0
192.168.0.1/32     *[IS-IS/160] 03:49:46, metric 11, tag2 1
                    > to 10.0.0.37 via fe-1/2/0.0
192.168.1.0/24     *[IS-IS/160] 03:49:46, metric 10
                    > to 10.0.0.37 via fe-1/2/0.0
192.168.1.1/32     *[IS-IS/160] 03:49:46, metric 11, tag2 1
                    > to 10.0.0.37 via fe-1/2/0.0
192.168.2.0/24     *[IS-IS/160] 03:49:46, metric 10
                    > to 10.0.0.37 via fe-1/2/0.0
192.168.2.1/32     *[IS-IS/160] 03:49:46, metric 11, tag2 1
                    > to 10.0.0.37 via fe-1/2/0.0
192.168.3.0/24     *[IS-IS/160] 03:49:46, metric 10
                    > to 10.0.0.37 via fe-1/2/0.0
192.168.3.1/32     *[IS-IS/160] 03:49:46, metric 11, tag2 1
                    > to 10.0.0.37 via fe-1/2/0.0

iso.0: 1 destinations, 1 routes (1 active, 0 holddown, 0 hidden)

Meaning

The 192.168/16 routes are redistributed into IS-IS.

Verifying Connectivity

Purpose
Action
Meaning

Purpose

Check that Device R1 can reach the destinations on Device R3.

Action

From operational mode, enter the ping command.

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user@R1> ping 192.168.1.1
PING 192.168.1.1 (192.168.1.1): 56 data bytes
64 bytes from 192.168.1.1: icmp_seq=0 ttl=63 time=2.089 ms
64 bytes from 192.168.1.1: icmp_seq=1 ttl=63 time=1.270 ms
64 bytes from 192.168.1.1: icmp_seq=2 ttl=63 time=2.135 ms

Meaning

These results confirm that Device R1 can reach the destinations in the OSPF network.

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IS-IS User Guide

ON THIS PAGE

Example: Redistributing OSPF Routes into IS-IS

Requirements

Overview

Topology

Configuration

Procedure

CLI Quick Configuration

Step-by-Step Procedure

Step-by-Step Procedure

Results

Verification

Verifying OSPF Route Advertisement

Purpose

Action

Meaning

Verifying Route Redistribution

Purpose

Action

Meaning

Verifying Connectivity

Purpose

Action

Meaning

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