Manual:Routing/OSPF: Difference between revisions

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<h3>Properties</h3>
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Command <code>/routing ospf monitor</code> will display current OSPF status.
Command <code>/routing ospf monitor</code> will display current OSPF status.
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Available read only properties:
Available read only properties:
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<h2>Area</h2>
<h2>Area</h2>
<p><b>Sub-menu:</b> <code>/routing ospf area</code></p>
<p><b>Sub-menu:</b> <code>/routing ospf area</code></p>
<br />
<h3>Description</h3>
<p>
OSPF allows collections of routers to be grouped together. Such a group is called an area. Each area runs a separate copy of the basic link-state routing algorithm. This means that each area has its own link-state database and corresponding shortest path tree.
<br /><br />
The structure of an area is invisible from other areas. This isolation of knowledge makes the protocol more scalable if multiple areas are used; routing table calculation takes less CPU resources and routing traffic is reduced.
<br /><br />
However, multi-area setups create additional complexity. It is not recommended separate areas with fewer than 50 routers. The maximum number of routers in one area is mostly dependent on CPU power you have for routing table calculation.
</p>
<h3>Properties</h3>


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     <td><var><b>lala</b></var> (<em>integer</em>; Default: <b></b>)</td>
     <td><var><b>area-id</b></var> (<em>IP address</em>; Default: <b>0.0.0.0</b>)</td>
    <td> OSPF area identifier. An area with area-id=0.0.0.0 (the backbone) must always be present. The backbone always contains all area border routers. The backbone is responsible for distributing routing information between non-backbone areas. The backbone must be contiguous, i.e. there must be no disconnected segments. However, area border routers do not need to be physically connected to the backbone - connection to it may be simulated using a [[virtual link]]. </td>
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    <td><var><b>default-cost</b></var> (<em>integer</em>; Default: <b>1</b>)</td>
    <td> specifies the cost for the default route originated by this stub area ABR. Applicable only for stub areas on ABRs </td>
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    <td><var><b>inject-summary-lsas</b></var> (<em>yes | no</em>; Default: <b>yes</b>)</td>
    <td> specifies whether to flood summary LSAs in this stub area. Applicable only for stub areas on ABRs </td>
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    <td><var><b>name</b></var> (<em>string</em>; Default: <b></b>)</td>
    <td> the name of the area </td>
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    <td><var><b>translator-role</b></var> (<em>integer</em>; Default: <b></b>)</td>
     <td> lalala </td>
     <td> lalala </td>
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    <td><var><b>type</b></var> (<em>default | nssa | stub</em>; Default: <b>default</b>)</td>
    <td> area type </td>
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<h3>Status</h3>


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<h2>Area Range</h2>
<h2>Area Range</h2>
<p><b>Sub-menu:</b> <code>/routing ospf area range</code></p>
<p><b>Sub-menu:</b> <code>/routing ospf area range</code></p>
<br />
<h3>Description</h3>
<p>
Prefix ranges are used to aggregate routing information on area boundaries.
By default, ABR creates a summary LSA for each route in specific area, and advertises it in adjacent areas.
Using 'ranges' allows to create only one summary LSA for multiple routes and send only single advertisement into adjacent areas,
or to suppress advertisements altogether.
If a range is configured as 'advertise=yes', a single summary LSA is advertised for each range if there are any routes under the range is the specific area. Else ('advertise=no') no summary LSAs area created and advertised outside area boundaries at all.
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<h3>Properties</h3>


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     <td><var><b>lala</b></var> (<em>integer</em>; Default: <b></b>)</td>
     <td><var><b>advertise</b></var> (<em>yes | no</em>; Default: <b>yes</b>)</td>
     <td> lalala </td>
    <td> whether to create summary LSA and advertise it to adjacent areas </td>
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    <td><var><b>area</b></var> (<em>string</em>; Default: <b></b>)</td>
    <td> the OSPF area associated with this range </td>
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    <td><var><b>cost</b></var> (<em>integer | default</em>; Default: <b>default</b>)</td>
    <td> the cost of the summary LSA this range will create
:<var>default</var> - the largest cost of all routes used (i.e. routers that fall within this range) </td>
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    <td><var><b>range</b></var> (<em>IP prefix</em>; Default: <b></b>)</td>
     <td> the network prefix of this range </td>
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Revision as of 08:39, 14 November 2008

Summary

MikroTik RouterOS implements OSPF Version 2 (RFC 2328). The OSPF protocol is the link-state protocol that takes care of the routes in the dynamic network structure that can employ different paths to its subnetworks. It always chooses shortest path to the subnetwork first.


General

Sub-menu: /routing ospf


Properties

Property Description
distribute-default (never | if-installed-as-type-1 | if-installed-as-type-2 | always-as-type-1 | always-as-type-2; Default: never) specifies how to distribute default route. Should be used for ABR (Area Border router) or ASBR (Autonomous System boundary router)
never - do not send own default route to other routers
if-installed-as-type-1 - send the default route with type 1 metric only if it has been installed (a static default route, or route added by DHCP, PPP, etc.)
if-installed-as-type-2 - send the default route with type 2 metric only if it has been installed (a static default route, or route added by DHCP, PPP, etc.)
always-as-type-1 - always send the default route with type 1 metric
always-as-type-2 - always send the default route with type 2 metric
metric-bgp (integer; Default: 20) the cost of the routes learned from BGP protocol
metric-connected (integer; Default: 20) the cost of the routes to directly connected networks
metric-default (integer; Default: 1) the cost of the default route
metric-rip (integer; Default: 20) the cost of the routes learned from RIP protocol
metric-static (integer; Default: 20) the cost of the static routes
redistribute-bgp (as-type-1 | as-type-2 | no; Default: no) redistribute all routes learned by the BGP protocol
redistribute-connected (as-type-1 | as-type-2 | no; Default: no) redistribute all connected routes, i.e., routes to directly reachable networks
redistribute-rip (as-type-1 | as-type-2 | no; Default: no) redistribute all routes learned by the RIP protocol
redistribute-static (as-type-1 | as-type-2 | no; Default: no) if enabled, the router will redistribute the information about static routes added to its routing database, i.e., routes that have been created using the '/ip route add' command on the router
router-id (IP address; Default: 0.0.0.0) the OSPF Router ID. If not specified, OSPF use one of router's IP addresses.


Notes

OSPF protocol supports two types of metrics:

  • type1 - external metrics are expressed in the same units as OSPF interface cost. In other words the router expects the cost of a link to a network which is external to AS to be the same order of magnitude as the cost of the internal links.
  • type2 - external metrics are an order of magnitude larger; any type2 metric is considered greater than the cost of any path internal to the AS. Use of type2 external metric assumes that routing between AS is the major cost of routing a packet, and eliminates the need conversion of external costs to internal link state metrics.

Monitor

Command /routing ospf monitor will display current OSPF status.


Available read only properties:

Property Description
state (down | running)
router-id (IP address)
dijkstras (integer)
db-exchanges (integer)
external-imports (integer)


Area

Sub-menu: /routing ospf area


Description

OSPF allows collections of routers to be grouped together. Such a group is called an area. Each area runs a separate copy of the basic link-state routing algorithm. This means that each area has its own link-state database and corresponding shortest path tree.

The structure of an area is invisible from other areas. This isolation of knowledge makes the protocol more scalable if multiple areas are used; routing table calculation takes less CPU resources and routing traffic is reduced.

However, multi-area setups create additional complexity. It is not recommended separate areas with fewer than 50 routers. The maximum number of routers in one area is mostly dependent on CPU power you have for routing table calculation.

Properties

Property Description
area-id (IP address; Default: 0.0.0.0) OSPF area identifier. An area with area-id=0.0.0.0 (the backbone) must always be present. The backbone always contains all area border routers. The backbone is responsible for distributing routing information between non-backbone areas. The backbone must be contiguous, i.e. there must be no disconnected segments. However, area border routers do not need to be physically connected to the backbone - connection to it may be simulated using a virtual link.
default-cost (integer; Default: 1) specifies the cost for the default route originated by this stub area ABR. Applicable only for stub areas on ABRs
inject-summary-lsas (yes | no; Default: yes) specifies whether to flood summary LSAs in this stub area. Applicable only for stub areas on ABRs
name (string; Default: ) the name of the area
translator-role (integer; Default: ) lalala
type (default | nssa | stub; Default: default) area type

Status


Area Range

Sub-menu: /routing ospf area range


Description

Prefix ranges are used to aggregate routing information on area boundaries. By default, ABR creates a summary LSA for each route in specific area, and advertises it in adjacent areas. Using 'ranges' allows to create only one summary LSA for multiple routes and send only single advertisement into adjacent areas, or to suppress advertisements altogether. If a range is configured as 'advertise=yes', a single summary LSA is advertised for each range if there are any routes under the range is the specific area. Else ('advertise=no') no summary LSAs area created and advertised outside area boundaries at all.

Properties

Property Description
advertise (yes | no; Default: yes) whether to create summary LSA and advertise it to adjacent areas
area (string; Default: ) the OSPF area associated with this range
cost (integer | default; Default: default) the cost of the summary LSA this range will create
default - the largest cost of all routes used (i.e. routers that fall within this range)
range (IP prefix; Default: ) the network prefix of this range


Network

Sub-menu: /routing ospf network

Property Description
lala (integer; Default: ) lalala


Interface

Sub-menu: /routing ospf interface

Property Description
lala (integer; Default: ) lalala


NBMA Neighbor

Sub-menu: /routing ospf nbma-neighbor

Property Description
lala (integer; Default: ) lalala


Virtual Link

Sub-menu: /routing ospf virtual-link

Property Description
lala (integer; Default: ) lalala


LSA

Sub-menu: /routing ospf lsa

Property Description
lala (integer; Default: ) lalala



Neighbor

Sub-menu: /routing ospf Neighbor

Property Description
lala (integer; Default: ) lalala


OSPF Router

Sub-menu: /routing ospf ospf-router

Property Description
lala (integer; Default: ) lalala


Route

Sub-menu: /routing ospf route

Property Description
lala (integer; Default: ) lalala