Configure Route Redistribution to OSPF

Before you begin

  • Enable OSPF globally.

  • Ensure that a route policy exists.

  • Ensure that you configure OSPF as the boundary router.

About this task

Configure a redistribute entry to announce certain routes into the OSPF domain, including DvR host routes, static routes, direct routes, Routing Information Protocol (RIP) routes, OSPF routes, IS-IS routes or Border Gateway Protocol (BGP) routes. Optionally, use a route policy to control the redistribution of routes.

Note

Note

Route policies treat permit and deny rules differently for inbound and outbound traffic.

  • For an in-policy (RIP, BGP) or an accept policy (OSPF) using a route-map, if a particular route is not explicitly denied in the accept policy or in-policy with the route-map, then the route is implicitly allowed.

  • For an out-policy (RIP, BGP) or a redistribute policy (RIP, OSPF, BGP) using a route-map, even if a particular route is not explicitly allowed in the redistribution policy or out-policy with the route-map, then the route is implicitly denied.

  • In order to permit or deny only explicit routes, configure a policy with additional sequences, where, the last sequence permits all routes that are not explicitly permitted or denied.

Procedure

  1. Enter OSPF Router Configuration mode:

    enable

    configure terminal

    router ospf

  2. Create the redistribution instance:

    redistribute <bgp|direct|isis|ospf|rip|static|dvr> [vrf-src WORD<1-16>]

  3. Apply a route policy if required:

    redistribute <bgp|direct|isis|ospf|rip|static|dvr> route-map WORD<0-64> [vrf-src WORD<1-16>]

  4. Optional: Enable route filtering using tags:
    redistribute isis auto-filter-tag
  5. Configure other parameters, as required.
  6. Enable the redistribution.

    redistribute <bgp|direct|isis|ospf|rip|static|dvr> enable [vrf-src WORD<1-16>]

  7. Ensure that the configuration is correct:

    show ip ospf redistribute [vrf WORD<1-16>] [vrfids WORD<0-512>]

  8. Exit to Global Configuration mode:

    exit

  9. Apply the redistribution.

    ip ospf apply redistribute <bgp|direct|isis|ospf|rip|static|dvr> [vrf WORD<1-16>] [vrf-src WORD<1-16>]

    Changes do not take effect until you apply them.

  10. View all routes (including DvR host routes) that are redistributed into OSPF:
    1. View the routes that are redistributed from the GRT to OSPF:

      show ip ospf lsdb

    2. View the routes that are redistributed to OSPF for a specific VRF instance:

      show ip ospf lsdb [vrf WORD<1–64>] [vrfids WORD<0–512>]

Examples

Redistribute static routes from the GRT to OSPF. Create the redistribution instance, apply a route policy, enable redistribution, and apply the redistribution.

Switch:1>enable
Switch:1#configure terminal
Switch:1(config)#router ospf
Switch:1(config-ospf)#redistribute static

WARNING: Routes will not be injected until apply command is issued after enable command
Switch:1(config-ospf)#redistribute static route-map policy1             
Switch:1(config-ospf)#redistribute static enable 
Switch:1(config-ospf)#exit
Switch:1(config)#ip ospf apply redistribute static 
Switch:1(config)#show ip ospf redistribute 

====================================================================================
                     OSPF Redistribute List - GlobalRouter
====================================================================================

SRC-VRF          SRC  MET MTYPE SUBNET   ENABLE RPOLICY
------------------------------------------------------------------------------------
GlobalRouter     STAT 0   type2 allow    TRUE   policy1
GlobalRouter      DVR 0   type2 allow    FALSE

Redistribute DvR host routes from the GRT to OSPF:

Switch:1>enable
Switch:1#configure terminal
Switch:1(config)#router ospf
Switch:1(config-ospf)#redistribute dvr
Switch:1(config-ospf)#redistribute dvr enable
Switch:1(config-ospf)#exit
Switch:1(config)#ip ospf apply redistribute dvr 
Switch:1(config)#show ip ospf redistribute

==============================================================
                     OSPF Redistribute List - GlobalRouter
==============================================================

SRC-VRF          SRC  MET MTYPE SUBNET   ENABLE RPOLICY
--------------------------------------------------------------
GlobalRouter     DVR  0   type2 allow    TRUE   test1

Redistribute DvR host routes to OSPF for a specific VRF vrf1:

Switch:1>enable
Switch:1#configure terminal
Switch:1(config)#router vrf vrf1
Switch:1(router-vrf)#ip ospf redistribute dvr
Switch:1(router-vrf)#ip ospf redistribute dvr enable
Switch:1(router-vrf)#exit
Switch:1(config)#ip ospf apply redistribute dvr vrf vrf1

View the DvR host routes that are distributed into OSPF:

Switch:1(config)#show ip ospf lsdb vrf vrf1


====================================================================================================
                              OSPF LSDB - VRF vrf1
====================================================================================================

                Router Lsas in Area 0.0.0.0

LSTYPE     LINKSTATEID     ADV_ROUTER      AGE  SEQ_NBR    CSUM
----------------------------------------------------------------------------------------------------
Router     192.0.2.1       192.0.2.1       1603 0x8000002d 0xf226    
Router     203.0.113.1     203.0.113.1     1608 0x8000002a 0x4104    

                Network Lsas in Area 0.0.0.0

LSTYPE     LINKSTATEID     ADV_ROUTER      AGE  SEQ_NBR    CSUM
----------------------------------------------------------------------------------------------------
Network    14.1.1.11       192.0.2.1       1635 0x80000003 0x4909    

                Summary Lsas in Area 0.0.0.0

LSTYPE     LINKSTATEID     ADV_ROUTER      AGE  SEQ_NBR    CSUM
----------------------------------------------------------------------------------------------------

                AsSummary Lsas in Area 0.0.0.0

                    






LSTYPE     LINKSTATEID     ADV_ROUTER      AGE  SEQ_NBR    CSUM
----------------------------------------------------------------------------------------------------

                NSSA Lsas in Area 0.0.0.0

LSTYPE     LINKSTATEID     ADV_ROUTER      AGE  SEQ_NBR    CSUM
----------------------------------------------------------------------------------------------------

                Opaque-Loc Lsas in Area 0.0.0.0

LSTYPE     LINKSTATEID     ADV_ROUTER      AGE  SEQ_NBR    CSUM
----------------------------------------------------------------------------------------------------

====================================================================================================
                                AsExternal Lsas
====================================================================================================

LSTYPE     LINKSTATEID     ADV_ROUTER      ETYPE  METRIC  ASE_FWD_ADDR    AGE  SEQ_NBR    CSUM      
----------------------------------------------------------------------------------------------------
AsExternal 101.1.1.3       203.0.113.1     2      1       0.0.0.0         1563 0x80000003 0xe7a7    
AsExternal 101.1.1.4       203.0.113.1     2      1       0.0.0.0         1477 0x80000003 0xddb0    
AsExternal 102.1.1.3       203.0.113.1     2      1       0.0.0.0         1528 0x80000003 0xdab3    

AsExternal 102.1.1.4       203.0.113.1     2      1       0.0.0.0         1480 0x80000003 0xd0bc    
AsExternal 103.1.1.3       203.0.113.1     2      1       0.0.0.0         1531 0x80000003 0xcdbf  
...
...
...

Variable Definitions

The following table defines parameters for the redistribute command.

Variable

Value
auto-filter-tag

Enables route filtering to ensure tagged routes are not redistributed into OSPF. The default is disabled.

enable

Enables the OSPF route redistribution instance.

metric <0–65535>

Configures the metric to apply to redistributed routes.

metric-type <type1|type2>

Specifies a type 1 or a type 2 metric. For metric type 1, the cost of the external routes is equal to the sum of all internal costs and the external cost. For metric type 2, the cost of the external routes is equal to the external cost alone.

route-map WORD<0-64>

Configures the route policy to apply to redistributed routes.

subnets <allow|suppress>

Allows or suppresses external subnet route advertisements when routes are redistributed into an OSPF domain.

vrf-src WORD<1-16>

Specifies the optional source VRF instance. You can use this variable with the other command variables.

<bgp | direct | isis | ospf | rip | static | dvr>

Specifies the type of routes to redistribute (the protocol source).

The following table defines parameters for the ip ospf apply redistribute command.

Variable

Value

vrf WORD<1-16>

Specifies the VRF instance.

vrf-src WORD<1-16>

Specifies the source VRF instance. You do not need to configure this parameter for redistribution within the same VRF.

WORD<0–32>

Specifies the type of routes to redistribute (the protocol source). Valid options are bgp, isis, direct, rip, ospf, or static.
9039040-00 Rev AB