Supported Platforms
Example: Configuring IS-IS on Logical Systems Within the Same Router
Introduction to Logical Systems
For many years, engineers have combined power supplies, routing hardware and software, forwarding hardware and software, and physical interfaces into a networking device known as a router. Networking vendors have created large routers and small routers, but all routers have been placed into service as individual devices. As a result, the router has been considered a single physical device for most of its history.
The concept of logical systems breaks with this tradition. With the Junos® operating system (Junos OS), you can partition a single router into multiple logical devices that perform independent routing tasks. Because logical systems perform a subset of the tasks once handled by the main router, logical systems offer an effective way to maximize the use of a single routing or switching platform.
 | Note: Beginning with Junos OS Release 9.3, the logical router feature has been renamed logical system. All configuration statements, operational commands, show command output, error messages, log messages, and SNMP MIB objects that contain the string logical-router have been changed to logical-system. |
Traditionally, service provider network design requires multiple layers of switches and routers. These devices transport packet traffic between customers. As seen on the left side of Figure 1, access devices are connected to edge devices, which are in turn connected to core devices.
However, this complexity can lead to challenges in maintenance, configuration, and operation. To reduce such complexity, Juniper Networks supports logical systems. Logical systems perform a subset of the actions of the main router and have their own unique routing tables, interfaces, policies, and routing instances. As shown on the right side of Figure 1, a set of logical systems within a single router can handle the functions previously performed by several small routers.
Figure 1: Logical Systems Concepts
Figure 2 shows the Junos OS architecture without logical systems configured. Figure 3 shows the Junos OS architecture when logical systems are configured. Note that each logical system runs its own routing protocol process (rpd).
Figure 2: Junos OS Without Logical Systems
Figure 3: Junos OS With Logical Systems
Example: Configuring IS-IS on Logical Systems Within the Same Router
This example shows how to configure an IS-IS network by using multiple logical systems that are running on a single physical router. The logical systems are connected by logical tunnel interfaces.
Requirements
You must connect the logical systems by using logical tunnel (lt) interfaces. See Example: Connecting Logical Systems Within the Same Router Using Logical Tunnel Interfaces.
Overview
This example shows an IS-IS configuration with three logical systems running on one physical router. Each logical system has its own routing table. The configuration enables the protocol on all logical tunnel interfaces that participate in the IS-IS domain.
Figure 4 shows the sample network.
Figure 4: IS-IS on Logical Systems
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.
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 IS-IS on logical systems:
- Configure the logical tunnel interface on Logical System
LS1 connecting to Logical System LS2.[edit logical-systems LS1]user@host# set interfaces lt-0/1/0 unit 2 description LS1->LS2user@host# set interfaces lt-0/1/0 unit 2 encapsulation ethernetuser@host# set interfaces lt-0/1/0 unit 2 peer-unit 1user@host# set interfaces lt-0/1/0 unit 2 family inet address 10.0.0.1/30user@host# set interfaces lt-0/1/0 unit 2 family iso
- Configure the logical tunnel interface on Logical System
LS1 connecting to Logical System LS3.[edit logical-systems LS1]user@host# set interfaces lt-0/1/0 unit 0 description LS1->LS3user@host# set interfaces lt-0/1/0 unit 0 encapsulation ethernetuser@host# set interfaces lt-0/1/0 unit 0 peer-unit 5user@host# set interfaces lt-0/1/0 unit 0 family inet address 10.0.1.2/30user@host# set interfaces lt-0/1/0 unit 0 family iso
- Configure the logical tunnel interface on Logical System
LS2 connecting to Logical System LS1.[edit logical-systems LS2]user@host# set interfaces lt-0/1/0 unit 1 description LS2->LS1user@host# set interfaces lt-0/1/0 unit 1 encapsulation ethernetuser@host# set interfaces lt-0/1/0 unit 1 peer-unit 2user@host# set interfaces lt-0/1/0 unit 1 family inet address 10.0.0.2/30user@host# set interfaces lt-0/1/0 unit 1 family iso
- Configure the logical tunnel interface on Logical System
LS2 connecting to Logical System LS3.[edit logical-systems LS2]user@host# set interfaces lt-0/1/0 unit 4 description LS2->LS3user@host# set interfaces lt-0/1/0 unit 4 encapsulation ethernetuser@host# set interfaces lt-0/1/0 unit 4 peer-unit 3user@host# set interfaces lt-0/1/0 unit 4 family inet address 10.0.2.2/30user@host# set interfaces lt-0/1/0 unit 4 family iso
- Configure the logical tunnel interface on Logical System
LS3 connecting to Logical System LS2.[edit logical-systems LS3]user@host# set interfaces lt-0/1/0 unit 3 description LS3->LS2user@host# set interfaces lt-0/1/0 unit 3 encapsulation ethernetuser@host# set interfaces lt-0/1/0 unit 3 peer-unit 4user@host# set interfaces lt-0/1/0 unit 3 family inet address 10.0.2.1/30user@host# set interfaces lt-0/1/0 unit 3 family iso
- Configure the logical tunnel interface on Logical System
LS3 connecting to Logical System LS1.[edit logical-systems LS3]user@host# set interfaces lt-0/1/0 unit 5 description LS3->LS1user@host# set interfaces lt-0/1/0 unit 5 encapsulation ethernetuser@host# set interfaces lt-0/1/0 unit 5 peer-unit 0user@host# set interfaces lt-0/1/0 unit 5 family inet address 10.0.1.1/30user@host# set interfaces lt-0/1/0 unit 5 family iso
- Configure the ISO address on the loopback interface for
the three logical systems.[edit logical-systems LS1]user@host# set interfaces lo0 unit 1 family iso address 49.0001.1720.1600.1001.00user@host# set protocols isis interface lo0.1 passive[edit logical-systems LS2]user@host# set interfaces lo0 unit 2 family iso address 49.0001.1720.1600.2002.00user@host# set protocols isis interface lo0.2 passive[edit logical-systems LS3]user@host# set interfaces lo0 unit 3 family iso address 49.0001.1234.1600.2231.00user@host# set protocols isis interface lo0.3 passive
- Configure IS-IS on all the interfaces.[edit logical-systems LS1 protocols isis]user@host# set interface lt-0/1/0.0user@host# set interface lt-0/1/0.2[edit logical-systems LS2 protocols isis]user@host# set interface lt-0/1/0.1 user@host# set interface lt-0/1/0.4[edit logical-systems LS3 protocols isis]user@host# set interface lt-0/1/0.5user@host# set interface lt-0/1/0.3
If you are done configuring the device, commit the configuration.
[edit]user@host# commit
Results
From configuration mode, confirm your configuration by issuing the show logical-systems command. If the output does not display the intended configuration, repeat the instructions in this example to correct the configuration.
user@host# show logical-systemsLS1 {
interfaces {
lt-0/1/0 {
unit 0 {
description LS1->LS3;
encapsulation ethernet;
peer-unit 5;
family inet {
address 10.0.1.2/30;
}
family iso;
}
unit 2 {
description LS1->LS2;
encapsulation ethernet;
peer-unit 1;
family inet {
address 10.0.0.1/30;
}
family iso;
}
}
lo0 {
unit 1 {
family iso {
address 49.0001.1720.1600.1001.00;
}
}
}
}
protocols {
isis {
interface lt-0/1/0.0;
interface lt-0/1/0.2;
interface lo0.1 {
passive;
}
}
}
}
LS2 {
interfaces {
lt-0/1/0 {
unit 1 {
description LS2->LS1;
encapsulation ethernet;
peer-unit 2;
family inet {
address 10.0.0.2/30;
}
family iso;
}
unit 4 {
description LS2->LS3;
encapsulation ethernet;
peer-unit 3;
family inet {
address 10.0.2.2/30;
}
family iso;
}
}
lo0 {
unit 2 {
family iso {
address 49.0001.1720.1600.2002.00;
}
}
}
}
protocols {
isis {
interface lt-0/1/0.1;
interface lt-0/1/0.4;
interface lo0.2 {
passive;
}
}
}
}
LS3 {
interfaces {
lt-0/1/0 {
unit 3 {
description LS3->LS2;
encapsulation ethernet;
peer-unit 4;
family inet {
address 10.0.2.1/30;
}
family iso;
}
unit 5 {
description LS3->LS1;
encapsulation ethernet;
peer-unit 0;
family inet {
address 10.0.1.1/30;
}
family iso;
}
}
lo0 {
unit 3 {
family iso {
address 49.0001.1234.1600.2231.00;
}
}
}
}
protocols {
isis {
interface lt-0/1/0.3;
interface lt-0/1/0.5;
interface lo0.3 {
passive;
}
}
}
} Verification
Confirm that the configuration is working properly.
Verifying That the Logical Systems Are Up
Purpose
Make sure that the interfaces are properly configured.
Action
user@host> show interfaces terseInterface Admin Link Proto Local Remote
...
lt-0/1/0 up up
lt-0/1/0.0 up up inet 10.0.1.2/30
iso
lt-0/1/0.1 up up inet 10.0.0.2/30
iso
lt-0/1/0.2 up up inet 10.0.0.1/30
iso
lt-0/1/0.3 up up inet 10.0.2.1/30
iso
lt-0/1/0.4 up up inet 10.0.2.2/30
iso
lt-0/1/0.5 up up inet 10.0.1.1/30
iso
... Verifying Connectivity Between the Logical Systems
Purpose
Make sure that the IS-IS adjacencies are established by checking the logical system routing entries and by pinging the logical systems.
Action
user@host> show route logical-system LS1inet.0: 5 destinations, 5 routes (5 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both
10.0.0.0/30 *[Direct/0] 3w0d 01:37:52
> via lt-0/1/0.2
10.0.0.1/32 *[Local/0] 3w0d 01:37:52
Local via lt-0/1/0.2
10.0.1.0/30 *[Direct/0] 3w0d 01:37:52
> via lt-0/1/0.0
10.0.1.2/32 *[Local/0] 3w0d 01:37:52
Local via lt-0/1/0.0
10.0.2.0/30 *[IS-IS/15] 3w0d 01:37:13, metric 20
> to 10.0.1.1 via lt-0/1/0.0
to 10.0.0.2 via lt-0/1/0.2
iso.0: 1 destinations, 1 routes (1 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both
49.0001.1720.1600.1001/72
*[Direct/0] 3w0d 01:37:52
> via lo0.1
user@host> show route logical-system LS2inet.0: 5 destinations, 5 routes (5 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both
10.0.0.0/30 *[Direct/0] 3w0d 01:38:01
> via lt-0/1/0.1
10.0.0.2/32 *[Local/0] 3w0d 01:38:01
Local via lt-0/1/0.1
10.0.1.0/30 *[IS-IS/15] 3w0d 01:37:01, metric 20
to 10.0.0.1 via lt-0/1/0.1
> to 10.0.2.1 via lt-0/1/0.4
10.0.2.0/30 *[Direct/0] 3w0d 01:38:01
> via lt-0/1/0.4
10.0.2.2/32 *[Local/0] 3w0d 01:38:01
Local via lt-0/1/0.4
iso.0: 1 destinations, 1 routes (1 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both
49.0001.1720.1600.2002/72
*[Direct/0] 3w0d 01:38:01
> via lo0.2
user@host> show route logical-system LS3inet.0: 5 destinations, 5 routes (5 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both
10.0.0.0/30 *[IS-IS/15] 3w0d 01:37:10, metric 20
to 10.0.2.2 via lt-0/1/0.3
> to 10.0.1.2 via lt-0/1/0.5
10.0.1.0/30 *[Direct/0] 3w0d 01:38:10
> via lt-0/1/0.5
10.0.1.1/32 *[Local/0] 3w0d 01:38:11
Local via lt-0/1/0.5
10.0.2.0/30 *[Direct/0] 3w0d 01:38:11
> via lt-0/1/0.3
10.0.2.1/32 *[Local/0] 3w0d 01:38:11
Local via lt-0/1/0.3
iso.0: 1 destinations, 1 routes (1 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both
49.0001.1234.1600.2231/72
*[Direct/0] 3w0d 01:38:11
> via lo0.3
From LS1, Ping LS3
user@host> set cli logical-system LS1user@host:LS1> ping 10.0.2.1PING 10.0.2.1 (10.0.2.1): 56 data bytes 64 bytes from 10.0.2.1: icmp_seq=0 ttl=63 time=1.264 ms 64 bytes from 10.0.2.1: icmp_seq=1 ttl=63 time=1.189 ms 64 bytes from 10.0.2.1: icmp_seq=2 ttl=63 time=1.165 ms ^C --- 10.0.2.1 ping statistics --- 3 packets transmitted, 3 packets received, 0% packet loss round-trip min/avg/max/stddev = 1.165/1.206/1.264/0.042 ms
From LS3, Ping LS1
user@host> set cli logical-system LS3user@host:LS3> ping 10.0.0.1PING 10.0.0.1 (10.0.0.1): 56 data bytes 64 bytes from 10.0.0.1: icmp_seq=0 ttl=63 time=1.254 ms 64 bytes from 10.0.0.1: icmp_seq=1 ttl=63 time=1.210 ms ^C --- 10.0.0.1 ping statistics --- 2 packets transmitted, 2 packets received, 0% packet loss round-trip min/avg/max/stddev = 1.210/1.232/1.254/0.022 ms
From LS1, Ping LS2
user@host> set cli logical-system LS1user@host:LS1> ping 10.0.2.2PING 10.0.2.2 (10.0.2.2): 56 data bytes 64 bytes from 10.0.2.2: icmp_seq=0 ttl=64 time=1.240 ms 64 bytes from 10.0.2.2: icmp_seq=1 ttl=64 time=1.204 ms 64 bytes from 10.0.2.2: icmp_seq=2 ttl=64 time=1.217 ms ^C --- 10.0.2.2 ping statistics --- 3 packets transmitted, 3 packets received, 0% packet loss round-trip min/avg/max/stddev = 1.204/1.220/1.240/0.015 ms
From LS2, Ping LS1
user@host> set cli logical-system LS2user@host:LS2> ping 10.0.1.2PING 10.0.1.2 (10.0.1.2): 56 data bytes 64 bytes from 10.0.1.2: icmp_seq=0 ttl=64 time=1.308 ms 64 bytes from 10.0.1.2: icmp_seq=1 ttl=64 time=1.235 ms ^C --- 10.0.1.2 ping statistics --- 2 packets transmitted, 2 packets received, 0% packet loss round-trip min/avg/max/stddev = 1.235/1.272/1.308/0.037 ms
From LS2, Ping LS3
user@host> set cli logical-system LS2user@host:LS2> ping 10.0.1.1PING 10.0.1.1 (10.0.1.1): 56 data bytes 64 bytes from 10.0.1.1: icmp_seq=0 ttl=64 time=1.253 ms 64 bytes from 10.0.1.1: icmp_seq=1 ttl=64 time=1.194 ms 64 bytes from 10.0.1.1: icmp_seq=2 ttl=64 time=1.212 ms 64 bytes from 10.0.1.1: icmp_seq=3 ttl=64 time=1.221 ms 64 bytes from 10.0.1.1: icmp_seq=4 ttl=64 time=1.195 ms ^C --- 10.0.1.1 ping statistics --- 5 packets transmitted, 5 packets received, 0% packet loss round-trip min/avg/max/stddev = 1.194/1.215/1.253/0.022 ms
From LS3, Ping LS2
user@host> set cli logical-system LS3user@host:LS3> ping 10.0.0.2PING 10.0.0.2 (10.0.0.2): 56 data bytes 64 bytes from 10.0.0.2: icmp_seq=0 ttl=64 time=1.240 ms 64 bytes from 10.0.0.2: icmp_seq=1 ttl=64 time=1.217 ms ^C --- 10.0.0.2 ping statistics --- 2 packets transmitted, 2 packets received, 0% packet loss round-trip min/avg/max/stddev = 1.217/1.228/1.240/0.012 ms
