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(module-ospf)=

OSPF Configuration Module

This configuration module configures OSPFv2 and OSPFv3 routing processes on most supported platforms (see supported features and platform support).

.. contents:: Table of Contents
   :depth: 2
   :local:
   :backlinks: none

Use **[netlab report](../netlab/report.md)** or **[netlab create -o report](../netlab/create.md)** commands to create reports on OSPF areas, routers, and interfaces. Use **[‌netlab show reports ospf](netlab-show-reports)** command to display available OSPF reports.

Supported Features

Supported OSPF features:

Missing features:

  • Virtual links
  • Opaque LSA
  • Multi-area adjacencies
  • Demand circuits
  • A gazillion nerd knobs and IETF quirks

Need one of those? Create a plugin and contribute it.

(ospf-platform)=

Platform Support

The following table describes per-platform support of individual router-level OSPF features:

Operating system Areas Reference
bandwidth		 OSPFv3 Route
import		 Default
route
Arista EOS ✅ ✅ ✅ ✅ ✅
Aruba AOS-CX ✅ ✅ ✅ ✅ ✅
Cisco IOSv/IOSvL2 ✅ ✅ ✅ ✅ ✅
Cisco IOS XRv ✅ ✅ ✅ ❌ ❌
Cisco IOS XE1 ✅ ✅ ✅ ✅ ✅
Cisco Nexus OS ✅ ✅ ✅ ❌ ❌
Cumulus Linux ✅ ✅ ✅ ✅ ✅
Dell OS10 (❗) ✅ ✅ ✅ ✅ ✅
Cumulus Linux 5.x (NVUE) ✅ ✅ ❌ ✅ ✅
Fortinet FortiOS ❗ ✅ ❌ ❌ ❌
FRR ✅ ✅ ✅ ✅ ✅
Junos2 ✅ ✅ ✅ ❌ ❌
Mikrotik RouterOS 6 ✅ ❌ ❌ ❌ ❌
Mikrotik RouterOS 7 ✅ ❌ ✅ ❌ ❌
Nokia SR Linux ✅ ✅ ✅ ✅ ❗ ✅ ❗
Nokia SR OS ✅ ✅ ✅ ✅ ❗ ❌
VyOS ✅ ✅ ✅ ✅ ✅

Notes:

  • Dell OS10 does not support OSPF on the so-called Virtual Network interface, the VLAN implementation model currently used in our templates.
  • Use the netlab show modules -m ospf command to display the route types that can be imported into OSPFv2/OSPFv3.

The following devices support BFD with OSPF:

Operating system BFD BFD
Strict-Mode
Arista EOS ✅ ❌
Aruba AOS-CX ✅ ❌
Cisco IOS ✅ ❌
Cisco IOS XE1 ✅ ❌
Cisco Nexus OS ✅ ❌
Cumulus Linux ✅ ❌
Dell OS10 ✅ ❌
Junos2 ✅ ❌
Mikrotik RouterOS 6 ✅ ❌
Nokia SR Linux ✅ ❌
Nokia SR OS ✅ ✅
VyOS ✅ ❌

Notes:

  • Mikrotik RouterOS and VyOS support BFD on OSPF only with the system default values for interval and multiplier.
See [OSPFv2](https://release.netlab.tools/_html/coverage.ospf.ospfv2) and [OSPFv3](https://release.netlab.tools/_html/coverage.ospf.ospfv3) Integration Tests Results for more details.

OSPF is also supported on these routing daemons:

Operating system Areas Reference
bandwidth		 OSPFv3 BFD BFD
Strict-Mode
BIRD ✅ ❌ ✅ ❌ ❌

(ospf-interface-support)= The following table documents the common interface-level OSPF features:

Operating system Cost Network
type		 Unnumbered
IPv4 interfaces		 Passive
interfaces
Arista EOS ✅ ✅ ✅ ✅
Aruba AOS-CX ✅ ✅ ✅ ✅
Cisco IOS ✅ ✅ ❌ ✅
Cisco IOS XE1 ✅ ✅ ✅ ✅
Cisco IOS XRv ✅ ✅ ✅ ✅
Cisco Nexus OS ✅ ✅ ✅ ✅
Cumulus Linux ✅ ✅ ✅ ✅
Cumulus Linux 5.x (NVUE) ✅ ✅ ✅ ✅
Dell OS10 ✅ ✅ ❌ ✅
Fortinet FortiOS ✅ ❗ ❌ ✅
FRR ✅ ✅ ✅ ✅
Junos2 ✅ ✅ ✅ ✅
Mikrotik RouterOS 6 ✅ ✅ ❌ ✅
Mikrotik RouterOS 7 ✅ ✅ ❌ ✅
Nokia SR Linux ✅ ✅ ✅ ✅
Nokia SR OS ✅ ✅ ✅ ✅
VyOS ✅ ✅ ✅ ✅

Notes:

  • Arista EOS, Cisco Nexus OS, SR Linux, and Dell OS10 support point-to-point and broadcast network types. Other network types will not be configured.
  • SR OS supports point-to-point, broadcast, and non-broadcast network types. It will not configure a point-to-multipoint network type.

OSPF routing daemons support these interface-level features:

Operating system Cost Network
type		 Unnumbered
IPv4 interfaces		 Passive
interfaces
BIRD ✅ ✅ ✅(*) ✅

Notes:

  • Routing daemons usually have a single interface. Running OSPF on them seems frivolous unless you need OSPF to get paths toward remote endpoints of IBGP sessions.
  • Unnumbered IPv4 interface support requires single unnumbered peer

(ospf-interface-optional-support)= These devices also support optional OSPF interface attributes:

Operating system Interface
timers		 Router
priority		 Cleartext
password		 MD5
digest
Arista EOS ✅ ✅ ✅ ❌
Aruba AOS-CX ✅ ✅ ✅ ❌
Cisco IOSv/IOSvL2 ✅ ✅ ✅ ❌
Cisco IOS XE1 ✅ ✅ ✅ ❌
Cisco Nexus OS ✅ ✅ ✅ ❌
Cumulus Linux 4.x ✅ ✅ ✅ ❌
Cumulus Linux 5.x (NVUE) ✅ ✅ ❌ ❌
Dell OS10 ✅ ✅ ✅ ❌
FRR ✅ ✅ ✅ ❌

OSPF routing daemons support these optional OSPF interface attributes:

Operating system Interface
timers		 Router
priority		 Cleartext
password		 MD5
digest
BIRD ✅ ✅ ✅ ❌

(ospf-node-parameters)=

Node Parameters

  • ospf.process -- process ID (default: 1)
  • ospf.af -- OSPF address families, usually set by the data transformation code. Configures OSPFv2 when ospf.af.ipv4 is set to True and OSPFv3 (on devices that support OSPFv3) when ospf.af.ipv6 is set to True.
  • ospf.area -- default OSPF area (default: 0.0.0.0). Used on links without explicit OSPF area and the loopback interface.
  • ospf.bfd -- enable BFD for OSPF (default: False)
  • ospf.bfd.strict enables RFC9355 BFD Strict-Mode (default: False)
  • ospf.default -- External default route origination (more details)
  • ospf.digest -- default OSPFv2 digest authentication parameters. Applies to all interfaces without an explicit ospf.digest setting.
  • ospf.import -- import (redistribute) routes into the global OSPF instance. By default, no routes are redistributed into the global OSPF instance.
  • ospf.password -- default OSPFv2 cleartext authentication password. Applies to all interfaces without an explicit ospf.password setting.
  • ospf.priority -- node-wide OSPF router priority. Applies to all interfaces without an explicit ospf.priority setting.
  • ospf.reference_bandwidth – per-node OSPF auto-cost reference bandwidth (in Mbps).
  • ospf.router_id -- set static router ID.
  • ospf.passive -- node-level default for passive interfaces (default: False)
  • ospf.timers -- default OSPF interface timers. You can override the node values on individual interfaces.

You can specify most node parameters as global values (top-level topology elements) or within individual nodes (see example for details).

VRF Parameters

  • You can use most OSPF node parameters (for example, area, digest, password, or timers) in VRF definitions to change the VRF OSPF instance configuration.
  • By default, netlab redistributes BGP- and connected routes into VRF OSPF instances on all network devices. You can change that on devices supporting configurable route import with the ospf.import VRF parameter.
  • You can change the router ID of a VRF OSPF instance with ospf.router_id parameter. Use this parameter when building back-to-back links between VRFs on the same node.
  • Set ospf.active to True to force a VRF to use OSPF even when no routers are attached to the VRF interfaces.
  • To disable OSPF in a VRF set ospf to False (see also ).
  • To originate a default route in a VRF OSPF instance, set the ospf.default VRF parameter (more details)

Link Parameters

  • ospf.area -- OSPF area. Use on ABRs; node-level OSPF area is recommended for intra-area routers.
  • ospf.bfd -- turn BFD for OSPF on or off on an individual link or interface (boolean value, overrides node ospf.bfd setting)
  • ospf.cost -- OSPF cost
  • ospf.digest -- A dictionary defining the OSPFv2 message digest (MD5 or SHA) authentication.
  • ospf.network_type -- Set OSPF network type. Allowed values are point-to-point, point-to-multipoint, broadcast and non-broadcast3. See also Default Link Parameters
  • ospf.passive -- explicitly enable or disable passive interfaces
  • ospf.password -- OSPFv2 cleartext interface authentication password
  • ospf.timers -- set OSPF interface timers. A dictionary containing dead and hello values (from 1 to 8192 seconds)4. Setting dead timer to one enables a sub-second hello timer on platforms supporting it.

Note: The same parameters can be specified for individual link nodes.

OSPF is automatically started on all interfaces within an autonomous system (interfaces with no EBGP neighbors; see also ). To disable OSPF on an intra-AS link, set ospf to False (see also ).

* Management interfaces are never added to the OSPF process. They are not in the set of device links and, thus, not considered in the OSPF configuration template.
* The OSPF configuration module is automatically removed from a node that does not run OSPF on any non-loopback interface or VRF. In that case, _netlab_ generates a warning that can be turned off by setting **‌defaults.ospf.warnings.inactive** to **‌False**.

(ospf-default-link)=

Default Link Parameters

Unless the OSPF network type is specified with the ospf.network_type, it's set to point-to-point on links with exactly two non-host nodes attached to them and left unspecified otherwise (implying platform default, which is almost always broadcast).

When the ospf.passive attribute is not specified on a link or an interface, netlab uses the link roles together with the link types to decide whether to include an interface in an OSPF process and whether to make an interface passive:

  • External links (links with role: external) are not included in the OSPF process.
  • Links with role set to passive are configured as passive OSPF interfaces.
  • Interfaces connected to links with a single router or routing daemon attached are passive OSPF interfaces.

Notes:

  • The BGP module could set the link role. Links with devices from different AS numbers attached to them get a role specified in defaults.bgp.ebgp_role parameter. The system default value of that parameter is external, excluding inter-AS links from the OSPF process.
  • Management interfaces are never added to the OSPF process. They are not in the set of device links and, thus, not considered in the OSPF configuration template.

(ospf-interface)=

Interface Parameters

Most OSPF interface parameters can be specified on the link and are copied into interface data and configured on lab devices; these parameters can only be set on individual interfaces:

  • ospf.priority -- OSPF router priority

(ospf-default)=

Specifying External Default Route

The ospf.default parameter specifies that the device should originate an external (E1 or E2) default route into an OSPF domain. It can be set to true or false; you can also be more specific and use the following settings:

  • ospf.default.always: set to True when you want the device to originate an OSPF default route, even when it does not have a default route itself.
  • ospf.default.cost: set the cost of the originated default route
  • ospf.default.type: the OSPF type of the external default route (e1 or e2).

Example

We want to create a three-router multi-area OSPF network:

  • R1 is a backbone area router
  • R2 is ABR between the backbone area and area 1
  • R3 is in an intra-area router in area 1.

All devices run OSPF:

module: [ ospf ]

The default OSPF area is 0.0.0.0:

ospf:
  area: 0.0.0.0

R1 and R2 are in default OSPF area (no need to specify per-node area):

nodes:
  r1:
    device: iosv
  r2:
    device: eos

R3 is in area 1. Non-default OSPF area must be specified within node data:

nodes:
  r3:
    device: nxos
    ospf:
      area: 0.0.0.1

The link between R1 and R2 is in area 0. No need to specify per-link area:

links:
- r1:
  r2:

The link between R2 and R3 is in area 1. Specify the OSPF area within the link definition:

links:
- r2:
  r3:
  ospf:
    area: 0.0.0.1

Alternatively, you could specify the OSPF area just for R2 (as R3 is already in area 1):

links:
- r2:
    ospf:
      area: 0.0.0.1
  r3:

Interesting details:

  • The default value for interface OSPF area is the node OSPF area
  • The default value for node OSPF area is the global OSPF area (default value: 0.0.0.0).
  • Due to the propagation of default values, the OSPF area for the R2-R3 link would be area 0 on R2 and area 1 on R3 -- you have to specify the OSPF area within the link definition or an individual node connected to the link.

Resulting Device Configurations

The above topology generates the following device configurations:

R1 (Cisco IOS)

router ospf 1
!
interface Loopback0
 ip ospf 1 area 0.0.0.0
!
interface GigabitEthernet0/1
 ip ospf 1 area 0.0.0.0
 ip ospf network point-to-point

R2 (Arista EOS)

router ospf 1
!
interface Loopback0
 ip ospf area 0.0.0.0
!
interface Ethernet1
 ip ospf area 0.0.0.0
 ip ospf network point-to-point
!
interface Ethernet2
 ip ospf area 0.0.0.1
 ip ospf network point-to-point

R3 (Cisco Nexus-OS)

feature ospf
!
router ospf 1
!
interface loopback0
 ip router ospf 1 area 0.0.0.1
!
interface Ethernet1/1
 ip router ospf 1 area 0.0.0.1
 ip ospf network point-to-point

Complete network topology:

module: [ ospf ]

ospf:
  area: 0.0.0.0

nodes:
  r1:
    device: iosv
  r2:
    device: eos
  r3:
    device: nxos
    ospf:
      area: 0.0.0.1

links:
- r1:
  r2:

- r2:
  r3:
  ospf:
    area: 0.0.0.1

Footnotes

  1. Includes Cisco CSR 1000v, Cisco Catalyst 8000v, Cisco IOS-on-Linux (IOL), and IOL Layer-2 image. ↩ ↩2 ↩3 ↩4

  2. Includes vMX, vSRX, vPTX, vJunos-switch, and vJunos-router ↩ ↩2 ↩3

  3. Some OSPF network types (non-broadcast or point-to-multipoint) are not supported by all platforms. ↩

  4. The values of hello and dead timer are not checked. It is possible to configure a hello timer that is larger than the corresponding dead timer, resulting in potential network device configuration errors. ↩