OSPF Tab Configuration¶

The options on this page configure the general behavior of OSPF in FRR, including various default values used when more specific options are not available.

Warning

When creating an initial OSPF configuration, configure the interfaces to be used with OSPF first. The interface configuration must exist before these general OSPF settings can be saved.

General Options¶

Enable:

Master enable switch for OSPF routing. When checked, FRR will start the OSPF routing daemon and attempt to use the OSPF settings in this section.

Log Adjacency Changes:

When set, instructs the OSPF daemon to log changes in neighbor adjacencies. This is useful for tracking changes to neighbor relationships, especially during initial configuration.

Router ID:

Typically the highest numbered local address on the firewall. This is also frequently set as the internal or LAN side IP address of a router. It does not matter what this ID is, so long as it is given in IPv4 address notation and does not conflict with any neighbors.

SPF Hold Time:

SPF timers determine when the router will make SPF routing decisions. Lowest time allowed between SPF calculations. Specified in milliseconds from 0-600000, with a default value of 1000.

The maximum time is calculated as 10x this value.

SPF calculations are adaptive, and if a new event occurs which would otherwise trigger a calculation before the hold timer expires, then the hold is increased by the SPF Hold Time value, up to the maximum. This avoids excessive consecutive recalculations.

SPF Delay:

Controls timers that determine when the router will make SPF routing decisions. Minimum time after an event occurs before allowing SPF calculation. Lower values will react faster to changes, but can be less stable. Specified in milliseconds from 0-600000, with a default value of 200.

Modules¶

Enable SNMP AgentX:: Enable agentx support for accessing FRR OSPF data via SNMP with the net-snmp package.

Default Area¶

Default Area:: Default OSPF area for this instance of OSPF. Used when an area is required but not defined elsewhere. See OSPF Area Configuration for details.
Default Area Type:: Sets the type for the Default Area. See Area Types and OSPF Area Configuration for details.

OSPF Networks¶

Warning

This section is deprecated and will not be covered here. Define areas and use areas on interfaces instead. Use summary routes instead, or use route-maps and distribute lists to limit distributed networks.

Route Redistribution¶

This section controls which, if any, IPv4 routes are redistributed to OSPF neighbors from other sources (Dynamic Routing Protocol Lists). OSPF can redistribute IPv4 routes from connected networks, kernel routes, BGP, and FRR static routes.

Redistribute:: Enables redistribution of routes from the given source.
Metric:: Advertise the routes from this source as having the given metric.
Metric Type:: The type of metric, either 1 or 2. See Metric Types for details about each type operates.
Route Map:: Apply the given route map to the redistributed route advertisements.
Distribute List:: Applies the given access list to routes redistributed from a given route source.

Default Route Redistribution¶

Redistribute:: Enables origination of a Type 5 AS-External LSA containing default route information into all areas capable of external routing.
Always Redistribute:: Always advertise a default route, even when a default route is not present in the local routing table.
Default Metric:: Advertise the default route as having the given metric.
Default Metric Type:: The type of metric, either 1 or 2. See Metric Types for details about each type operates.
Route Map:: Apply the given route map to the outbound default route advertisement.

Advanced¶

RFC 1583 Compatibility:

Enables compatibility with the older OSPF standard from RFC 1583, which has been obsoleted by the newer RFC 2328. The specific change this option enables relates to external path preference calculation and routing loop prevention. See RFC 2328 section G.2 for specific details.

Opaque LSA:

Enables support for Opaque LSAs, as described in RFC 2370.

Reference Bandwidth:

A base value, in Mbit/s, which is used when OSPF automatically calculates cost values. The default value is 100 which means that an interface with 100Mbit/s of bandwidth or greater will have a cost of 1, with lower bandwidth values incurring higher cost values.

All routers in the same area should use the same value, otherwise automatic cost calculations would fail to accurately represent total path costs between routers.

Max Metric:

Administratively Enable Max Metric:

Sets the administrative distance of routes through this router to infinity, so that other routers will avoid using this router to reach other networks. Networks on this router are still reachable. See RFC 3137 for more information.

Startup Seconds:

Conditionally sets the administrative distance of routes through this router to infinity for a period of time after startup.

This allows other routers in the area to avoid using routes through this router until a full convergence is achieved.

Shutdown Seconds:

Conditionally sets the administrative distance of routes through this router to infinity for a period of time after shutdown.

This allows other routers in the area to avoid using routes through this router until a full convergence is achieved.

Write Multiplier:

Number of interfaces processed per write operation, from 1-100. Default value is 20.

ABR Type:

Controls the behavior of Area Border Router (ABR) functionality.

cisco|ibm:: The default behavior of OSPF in FRR, discussed in RFC 3509. This behavior allows an ABR without a backbone connection to act as an internal router for all connected areas.
shortcut:: Discussed in draft-ietf-ospf-shortcut-abr-02, this behavior allows ABRs to consider summary LSAs from all attached areas, rather than being forced to route through a suboptimal path only because it is shorter.
standard:: The ABR behavior described in the original OSPF standard. When set, a router attached to multiple areas requires a connection to a backbone. If no backbone is available, traffic attempting to cross areas will be dropped.