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You can configure only one routing instance per logical interface.
A routing instance is a routing entity for a router. You can configure multiple routing instances of OSPF. Each instance contains a routing table, applied routing policies, routing table group, interfaces that belong to that instance, and an OSPF configuration related to that instance.
You configure a primary routing instance at the [edit protocols] hierarchy level. You configure additional routing instances at the [edit routing-instances] hierarchy level.
This chapter includes the following topics:
To configure routing instances, include the following statements at the [edit routing-instances] and [edit routing-options] hierarchy levels of the configuration:
[edit]
routing-instances {
routing-instance-name {
interface interface-name {
protocols {
ospf {
ospf-configuration;
}
}
routing-options {
aggregate {
defaults {
aggregate-options;
}
route destination-prefix {
policy policy-name;
aggregate-options;
}
}
autonomous-system autonomous-system <loops number>;
confederation confederation-autonomous-system members autonomous-system;
fate-sharing {
cost value;
from address [to address];
}
forwarding-table {
export [ policy-names ];
}
generate {
defaults {
generate-options;
}
route destination-prefix {
policy policy-name;
generate-options;
}
}
interface-routes {
rib-group routing-table-name;
}
martians {
destination-prefix match-type <allow>;
}
multicast {
scope scope-name {
interface [ interface-name ];
prefix destination-prefix;
}
}
options {
syslog (level level | upto level);
}
rib routing-table {
static {
defaults {
static-options;
}
route destination-prefix {
next-hop;
static-options;
}
}
}
aggregate {
defaults {
aggregate-options;
}
route destination-prefix {
policy policy-name;
aggregate-options;
}
}
generate {
defaults {
generate-options;
}
route destination-prefix {
policy policy-name;
generate-options;
}
}
martians {
destination-prefix match-type <allow>;
}
}
rib-group {
group-name {
import-rib [ routing-table-name ];
export-rib routing-table-name;
}
}
route-record;
router-id address;
{
defaults {
static-options;
}
route destination-prefix {
next-hop;
static-options;
}
}
traceoptions {
file name <replace> <size size> <files number> <no-stamp> <world-readable>;
flag flag <flag-modifier> <disable>;
}
}
For more detailed information, see [edit routing-options] Hierarchy Level and [edit protocols] Hierarchy Level.
To configure routing instances for OSPF, you must include at least the following statements in the configuration:
[edit]
protocols {
ospf {
rib-group common;
area area-id {
interface all;
}
}
}
routing-instances {
routing-instance-name {
interface interface-name;
protocols {
ospf {
rib-group common;
area area-id {
interface all;
}
}
routing-options {
rib-groups {
common {
import-rib [inet.0 routing-instance-name.inet.0];
}
}
}
policy-statement apply-tag {
term instance-name1 {
from instance routing-instance-name1;
then {
tag string1;
accept;
}
}
term routing-instance-name2 {
from instance routing-instance-name2;
then {
tag string2;
accept;
}
}
policy-statement filter-on-routing-instance-name1 {
from protocol ospf;
tag string1;
}
then accept;
}
}
policy-statement filter-on-routing-instance-name2 {
from protocol ospf;
tag string2;
}
then accept;
}
}
|
You can configure only one routing instance per logical interface. |
To configure multiple routing instances, perform the following tasks:
[edit protocols ospf] hierarchy level with the statements needed for your network so that routes are installed in inet.0 and therefore are installed in the forwarding table. Make sure to include the routing table group. For more information, see Configure the Primary OSPF Instance and Configure a Routing Table Group.
inet.0 routing table. You can do this in two ways:
inet.0 to keep the routes from going to other instances.
Figure 7 shows how you can use multiple routing instances of OSPF to segregate traffic within a large network. The network consists of three administrative entities: voice_policy, other_policy, and the backbone or core. Each entity is composed of several geographically separate sites that are connected by the backbone and managed by the backbone entity.
Sites A and D belong to the voice_policy routing instance. Sites B and C belong to the other_policy instance. Router 1 and Router 3 at the edge of the backbone connect the routing instances. Each run a separate OSPF instance (one per entity).
Router 1 runs three OSPF instances: one each for Site A (voice_policy), Site D (other_policy), and the backbone otherwise known as the primary instance. Router 3 also runs three OSPF instances; one each for Site B (other_policy), Site C (voice_policy), and the backbone (primary instance).
OSPF routes learned in one voice_policy site are distributed across the backbone instance to the other voice_policy site. Additionally, OSPF routes learned in one other_policy site are distributed across the core to the other_policy site.
The backbone OSPF instance exports OSPF routes learned in the other instances and installs them in the backbone instances routing table as external routes tagged with their respective entity identifiers. The export policies select a routing instance from a route source and set the OSPF tag to a unique number corresponding to the routing instance entity.
External routes learned in the backbone OSPF instance are installed in routing tables of the three instances. Tags on these routes identify the entity to which they belong. The OSPF instance for to the voice_policy entity then exports these routes (learned from the backbone but also installed in the voice_policy routing table) into the voice_policy site if the tag on a route is appropriate (the same as the voice_policy entity identifier). Similarly, the OSPF instance corresponding to the other_policy entity exports routes tagged as other_policy entity routes into the other_policy entity. Export policies select OSPF external route tags to export them to the correct entity OSPF instance.
The sections that follow describe how to configure Router 1 in the backbone entity with multiple routing instances.
Configure the routing instances for voice_policy and other_policy. Use all routes learned from the routing tables in the routing table group common. Export routes tagged as belonging to the routing instance:
[edit]
routing-instances {
voice_policy {
interface so-2/2/2.0;
protocols {
ospf {
rib-group common;
export filter-on-voice-policy;
area 0.0.0.0 {
interface all;
}
}
routing-options;
other_policy {
interface so-4/2/2.0;
protocols {
ospf {
rib-group common;
export filter-on-other-policy;
area 0.0.0.0 {
interface all;
}
}
routing-options {...};
Configure the routing table group common to share routes with inet.0 (in the backbone entity), the voice_policy.inet.0, and the other_policy.inet.0 routing tables:
[edit]
routing-options {
rib-groups {
common {
import-rib [inet.0 voice_policy.inet.0 other_policy.inet.0];
}
}
}
Configure an export policy statement that a routing instance uses to export and tag OSPF routes learned from the routing instances:
[edit]
policy-options {
policy-statement apply-tag {
term voice_policy {
from instance voice_policy;
then {
tag 10;
accept;
}
}
}
}
term other_policy {
from instance other_policy;
then {
tag 12;
accept;
}
}
}
}
policy-statement filter-on voice_policy {
from protocol ospf;
tag 10;
}
then accept;
}
}
}
}
policy-statement filter-on other_policy {
from protocol ospf;
tag 12;
}
then accept;
}
}
}
}
Configure the primary OSPF instance so that the routes learned from the routing instances are installed in inet.0 and to export the tagged routes from voice_policy and other_policy:
[edit]
protocols {
ospf {
rib-group common;
export filter-on-voice_policy;
export filter-on-other_policy;
area 0.0.0.0 {
interface so-2/2/2.0;
interface so-4/2/2.0;
passive;
}
}
}
}
The configuration for Router 3 is the same as for Router 1 except that the interface names might differ. In this example, the interface so-5/2/2.0 belongs to other_policy and so-3/2/2.0 belongs to voice_policy.
The following sections explain each of the routing instances configuration statements. The statements are organized alphabetically.