OSPF Area Configuration

OSPF Areas are managed at Services > FRR OSPF on the Areas tab.

The Areas tab contains a list of current OSPF areas, if any, and controls to manage the entries (e.g. edit, delete). The Add button creates a new area.

The remaining sections on this page cover the various options available when creating or editing an area entry.

Area Options

Area:

A designation for the set of networks. Can be any number capable of being expressed in dotted quad notation (IPv4 address) or as a 32-bit unsigned integer.

In typical OSPF configurations 0.0.0.0 is the backbone area between all routers and each local network has its own area. For simpler deployments, the only area may be 0.0.0.0 on every router and interface. Using a single area disables some features such as route summarization.

Description:

Some text describing this area.

Area Type:

Defines how this area behaves. For a list of all types and how they operate, see Area Types.

Default Route Cost:

Sets the cost applied to default route summary LSA messages sent to stub areas.

ABR Shortcut:

For use with ABR Type set to Shortcut (Advanced), this advertises the area as capable of supporting ABR shortcut behavior (draft-ietf-ospf-shortcut-abr-02).

Authentication

This option enables authentication for this area. Communication from peers must contain the expected authentication information to be accepted, and outgoing packets will have authentication information added.

Authentication passwords and keys are configured by the OSPF interface settings.

Authentication Type:

Sets the type of authentication to use in this area.

None:

Do not use authentication in this area.

Message Digest (MD5 Hash):

Enables MD5 HMAC authentication for this area. This is stronger authentication than simple passwords.

Simple Password:

Enables simple password authentication for this area.

Route Summarization

Configure summarization of routes inside the given prefixes. Instead of Type 1 (Router) and Type 2 (Network) LSAs, it creates Type 3 Summary LSAs instead.

The options here can be repeated for multiple prefixes. Click Add for each additional prefix.

Summary Prefix:

The prefix to summarize.

Do Not Advertise:

Disable advertisement for this prefix.

Cost:

Apply the specified cost to summarized routes for this prefix.

Substitute Prefix:

Instead of advertising the first prefix, advertise this prefix instead.

ABR Summary Route Filtering

Export List:

Uses the given ACL to limit Type 3 summary LSA messages for intra-area paths that would otherwise be advertised. This behavior only applies if this router is the ABR for the area in question.

Import List:

Similar to export-list, but for routes announced by other routers into this area.

Filter List (Out|In):

Similar to Export List and Import List but uses prefix lists instead of ACLs, and can work in either direction.