AIS AI2524 Manuel D’Utilisation
Chapter 8: AI2524 Protocol Configuration Steps
August 1997
Page 8-9
2524UM
Configure Route Calculation Timers
You can configure the delay time between when OSPF receives a to-
pology change and when it starts a Shortest Path First (SPF) calcula-
tion. You can also configure the hold time between two consecutive
SPF calculations. Type this command in router configuration mode:
pology change and when it starts a Shortest Path First (SPF) calcula-
tion. You can also configure the hold time between two consecutive
SPF calculations. Type this command in router configuration mode:
timers spf
spf-delay spf-holdtime
Configure OSPF over On-Demand Circuits
The OSPF on-demand circuit is an enhancement to the OSPF protocol
that allows efficient operation over on-demand circuits like ISDN,
X.25 SVCs, and dial-up lines. This feature supports RFC 1793, ex-
tending OSPF to Support Demand Circuits.
that allows efficient operation over on-demand circuits like ISDN,
X.25 SVCs, and dial-up lines. This feature supports RFC 1793, ex-
tending OSPF to Support Demand Circuits.
With this feature, periodic hellos are suppressed and the periodic re-
freshes of LSAs are not flooded over the demand circuit.
freshes of LSAs are not flooded over the demand circuit.
To configure OSPF for on-demand circuits, perform these tasks:
1.
Enable OSPF operation.
router ospf
process-id
2.
Configure OSPF on an on-demand circuit.
ip ospf demand-circuit
If the router is part of a point-to-point topology, then only one end of
the demand circuit must be configured with this command. However,
all routers must have this feature loaded.
the demand circuit must be configured with this command. However,
all routers must have this feature loaded.
If the router is part of a point-to-multipoint topology, only the multi-
point end must be configured with this command.
point end must be configured with this command.
Implementation Considerations
Because LSAs that include topology changes are flooded over an on-
demand circuit, it is advised to put demand circuits within OSPF.
demand circuit, it is advised to put demand circuits within OSPF.