Ospf Dynamic Cost; Ospf Limitations; Ospf Commands - Avaya G250 Administration Manual

OSPF dynamic Cost

An OSPF interface on the G250/G350 can dynamically set a Cost. The Cost represents the
price assigned to each interface for purposes of determining the shortest path.
By default the OSPF interface Cost is calculated based on the interface bandwidth, according to
the following formula:
Cost = 100,000 / bandwidth (in kbps)
The result is that the higher the bandwidth, the lower the Cost.
To manually configure the Cost of an OSPF interface, use the ip ospf cost command from
the interface context. By using this option, dynamic bandwidth updates do not change the Cost.
Use the no ip ospf cost command to return to dynamic cost calculation on an interface.
Use the bandwidth command from the Interface context to manually adjust the interface's
bandwidth. If Cost is being determined dynamically, it is this configured bandwidth and not the
actual interface bandwidth which is used to calculate Cost.

OSPF limitations

You can configure the G250/G350 as an OSPF Autonomous System Boundary Router (ASBR)
using route redistribution. The G250/G350 can be installed in the OSPF backbone area (area
0.0.0.0) or in any OSPF area that is part of a multiple areas network. However, the G250/G350
cannot be configured to be an OSPF area border router itself.
The G250/G350 supports the ECMP equal-cost multipath (ECMP) feature which allows load
balancing by splitting traffic between several equivalent paths.
While you can activate OSPF with default values for each interface using a single command,
you can configure many of the OSPF parameters.

OSPF commands

Use the following commands to configure OSPF. For more information about these commands,
see Avaya G250 and Avaya G350 CLI Reference, 03-300437.
Use the area command to configure the OSPF area ID of the router. Use the no form of
●
the command to delete the OSPF area id.
Use the default-metric command to set the interface OSPF route metric value. Use
●
the no form of this command to restore the default value.
Use the ip ospf authentication command to specify the authentication type for an
●
interface. Use the no form of this command to remove the authentication type for an
interface.
Configuring OSPF
Issue 5 June 2008 537