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OSPF Tab

Configuration > Networking > Routing > OSPF

This tab manages OSPF (Open Shortest Path First) on LAN and WAN interfaces.

OSPF learns routes from routing peers, and then subnet shares them with EdgeConnect peers and/or BGP neighbors.

A route tag is applied to a route to better identify the source of the network it originated from. It is primarily used to filter routes from being redistributed in a routing loop.

A maximum of 64 OSPF neighbors and 64 BGP peers is supported per appliance, with 200 next-hops supported per interface.

  • For BGP, only 64 peers can be added. For OSPF, more than 64 neighbors can be added, though an error will be logged.

  • If more than 64 OSPF neighbors are added, the active OSPF neighbors are chosen in a deterministic manner. All OSPF neighbors that are added are queried in a sorted order using segment ID as the primary index and the neighbor IP address as the secondary index. For example, if there are 65 OSPF neighbors, the peer in the highest segment and with the highest IP address will be the one that is always dropped. It will not drop a random OSPF neighbor.

  • Also, if there are 60 OSPF neighbors in the default segment, which always has ID:0, and 10 OSPF neighbors in segment 1, the 60 neighbors in the default segment will always be included, as well as the 4 neighbors in segment 1 with the lowest IP addresses.

Filter by Segment

To filter the rows displayed in the OSPF table by segment:

  • Select Default from the Segment drop-down list to display for the system-supplied default segment, or

  • Select one of the other listed segments, which reflect the custom segments defined using Routing Segmentation (Configuration > Networking > Routing > Routing Segmentation (VRF)).

Select All to display for all segments, which is the default setting

The table below describes the fields displayed for the OSPF configuration.

Field Description
Appliance Name of the appliance.
Segment Name of the segment being used, if enabled.
Enable [Route Metric] Cost associated with a route. The higher the value, the less preferred.
Router ID This router identifier is the IPv4 address by which the remote peer can identify this appliance for purposes of OSPF.
Redistribute Routes to OSPF Redistribution map being used to redistribute routes to OSPF.
Details Additional details about the route.

Select the edit icon in the OSPF table to edit and enable OSPF.

OSPF Edit Row

Use this dialog box to manage OSPF (Open Shortest Path First) on LAN and WAN interfaces.

OSPF learns routes from routing peers, and then subnet shares them with EdgeConnect peers and/or BGP neighbors.

Field Description
Enable OSPF When enabled, the appliance has access to use the OSPF protocol.
Router ID IPv4 address of the router that the remote peer uses to identify the appliance for purposes of OSPF.
Redistribute routes to OSPF Redistributing routes into OSPF from other routing protocols or from static will cause these routes to become OSPF external routes. Select the edit icon to the left of this field and select the OSPF route redistribution maps you would like to select.

To add an additional interface to an OSPF route, click Add in the Interfaces section.

NOTE: The BFD field in the Interfaces table on the OSPF dialog box is set to N/A if BFD is not supported on the appliance.

To configure or modify an OSPF route map, select the edit icon next to the Redistribute routes to OSPF field.

Add Interface

Complete the following fields to add an interface to OSPF.

Field Description
Interface Indicates whether a Backup Designated Router (BDR) is specified for the Designated Router (DR). Options are Yes or No.
Area ID Number of the area in which to locate the interface. The Area ID is the same for all interfaces.

It can be an integer between 0 and 4294967295, or it can take a form similar to an IP address, A.B.C.D.
Cost The cost of an interface in OSPF is an indication of the overhead required to send packets across a certain interface. It is used in the OSPF path calculation to determine link preference.
Priority Router priority. (If two or more best routes are subnet shared, peer priority is used as the tiebreaker.)
Admin Status Indicates whether the interface is set to admin UP or DOWN.
Hello Interval Specifies the length of time, in seconds, between the hello packets that a router sends on an OSPF interface.
Dead Interval Number of seconds that a router’s Hello packets have not been seen before its neighbors declare the OSPF router down.
Transmit Delay Number of seconds required to transmit a link state update packet. Valid values are 1 to 65535.
Retransmit Interval Amount of time (in seconds) the router will wait to send retransmissions if the router receives no acknowledgment.
BFD Select this check box to enable BFD for the OSPF interface. This field is not displayed if BFD is not supported on the appliance.

NOTE: Before you select this check box, enable and configure BFD from the BFD tab.
Authentication None – No authentication.

Text – Simple password authentication allows a password (key) to be configured per area.

MD5 – Message Digest authentication is a cryptographic authentication. A key (password) and key-id are configured on each router. The router uses an algorithm based on the OSPF packet, the key, and the key-id to generate a “message digest” that gets appended to the packet.
Comment Any information you want to include for your own use.

OSPF Route Redistribution Maps

Route Maps are policies applied to IP routes during redistribution between routing protocols. They have Match Criteria and Set Actions that allow for filtering routes or modifying metrics and attributes for routes that meet the criteria defined in the match statement. Route-map rules follow a top-down order based on the sequence number defined for each entry.

EdgeConnect Enterprise supports applying Route Maps inbound from and outbound to BGP peers and outbound to OSPF neighbors and the SD-WAN Fabric. It is best practice to use Orchestrator to apply Route Maps using templates.

You can specify up to 20 OSPF route maps and 128 rules per route map.

You can specify up to 6 prefixes for each rule applied to a route map.

You can add, delete, rename, or clone route maps using this window. You can add rules to your route map by clicking Add Rule. A route map without any enabled rules is treated as a default deny all.

Prefix Match Criteria

The default for prefix match criteria is exact-match + greater-than. Both the specified prefix and any subnets of that prefix will be matched, up to a length of 32 for IPv4 or 128 for IPv6 (subnet sharing route maps only).

Less-than-or-equal-to (LE) and greater-than-or-equal-to (GE) clauses can also be applied to specify the inclusion of certain subnets.

To match a default-route, deny 0.0.0.0/1, deny 128.0.0.0/1, and then permit any.

GE Clause

If a GE clause is applied, the rule will also include all prefixes that have a prefix length greater than or equal to the GE value and less than or equal to 32 or 128 (for IPv6).

Example: A.B.C.D/X GE Y

In this example the following will be included:

  • The exact match to A.B.C.D/X

  • All the prefixes that belong to the subnet A.B.C.D/X that have a length greater than or equal to Y and less than or equal to 32

LE Clause

If an LE clause is applied, the rule will also include all prefixes that have a prefix length less than or equal to the LE value.

Example: A.B.C.D/X LE Y

In this example the following will be included:

  • The exact match to A.B.C.D/X

  • All the prefixes that belong to the subnet A.B.C.D/X that have a length greater than or equal to X and less than or equal to 32

  • All the prefixes that belong to the subnet A.B.C.D/X that have a length less than or equal to Y

Combining LE and GE Clauses

Example: A.B.C.D/X LE Y GE Z

In this example the following will be included:

  • The exact match to A.B.C.D/X

  • All the prefixes that belong to the subnet A.B.C.D/X that have a length less than or equal to Y

  • All the prefixes that belong to the subnet A.B.C.D/X that have a length greater than or equal to Z and less than or equal to 32

Exact Match

If both GE and LE clauses are specified and are equal, the rule will result in an exact match.

Example: A.B.C.D/X LE Y GE Y

In this example, the following will be included:

  • The exact match to A.B.C.D/X

  • The exact match to the subnet A.B.C.D/X that has a length equal to Y

You can specify the following fields in each rule for the selected route map.

Priority

Field Description
Priority If you are using Orchestrator templates to add rules, Orchestrator will delete all entries from 1000 – 9999 before applying its policies.

You can create rules with higher priority than Orchestrator rules (1 – 999) and rules with lower priority (10000 – 19999 and 25000 – 65534).

NOTE: The priority range from 20000 to 24999 is reserved for Orchestrator.

When adding a rule, the priority is incremented by 10 from the previous rule. The priority can be changed, but this default behavior helps to ensure you can insert new rules without having to change subsequent priorities.

Select Match Criteria

Source Protocol Complete the Following Fields (based on protocol selected)
Local/Static Prefix + optional LE/GE parameters
BGP Prefix + optional LE/GE parameters

BGP Communities
SD-WAN Routes Prefix + optional LE/GE parameters

BGP Communities

OSPF Tag

NOTE: The above fields in the right column will change depending on the source protocol chosen.

Set Actions

Field Description
Permit Enable or disable. This setting allows or denies the route map.
OSPF Tag Value of OSPF tag to set in routing information sent to destination.
OSPF Metric Type Filters redistributed routes to OSPF.
Metric Metric for the route.
Comment Comment you want to include.

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