Administrator Guide

Setting the convergence parameter (from 1 to 4) indicates the actual convergence level. Each convergence setting adjusts
the LSA parameters to zero, but the fast-convergence parameter setting allows for even finer tuning of the convergence
speed. The higher the number, the faster the convergence.
To enable or disable fast-convergence, use the following command.
● Enable OSPF fast-convergence and specify the convergence level.
CONFIG-ROUTEROSPF- id mode
fast-convergence {number}
The parameter range is from 1 to 4.
The higher the number, the faster the convergence.
When disabled, the parameter is set at 0.
NOTE: A higher convergence level can result in occasional loss of OSPF adjacency. Generally, convergence level 1
meets most convergence requirements. Only select higher convergence levels following consultation with Dell Technical
Support.
In the following examples, Convergence Level shows the fast-converge parameter setting and Min LSA origination
shows the LSA parameters (shown in bold).
The following example shows the fast-converge command.
Dell(conf-router_ospf-1)#fast-converge 2
Dell(conf-router_ospf-1)#ex
Dell(conf)#ex
Dell#show ip ospf 1
Routing Process ospf 1 with ID 192.168.67.2
Supports only single TOS (TOS0) routes
SPF schedule delay 5 secs, Hold time between two SPFs 10 secs
Convergence Level 2
Min LSA origination 0 secs, Min LSA arrival 0 secs
Number of area in this router is 0, normal 0 stub 0 nssa 0
Dell#
To disable fast-convergence, use the no fast-converge command.
Dell#(conf-router_ospf-1)#no fast-converge
Dell#(conf-router_ospf-1)#ex
Dell#(conf)#ex
Dell##show ip ospf 1
Routing Process ospf 1 with ID 192.168.67.2
Supports only single TOS (TOS0) routes
SPF schedule delay 5 secs, Hold time between two SPFs 10 secs
Convergence Level 0
Min LSA origination 5 secs, Min LSA arrival 1 secs
Number of area in this router is 0, normal 0 stub 0 nssa 0
Dell#
Changing OSPFv2 Parameters on Interfaces
You can modify the OSPF configuration on switch interfaces.
Some interface parameter values must be consistent across all interfaces to avoid routing errors. For example, set the same
time interval for the hello packets on all routers in the OSPF network to prevent misconfiguration of OSPF neighbors.
To change OSPFv2 parameters on the interfaces, use any or all of the following commands.
● Change the cost associated with OSPF traffic on the interface.
CONFIG-INTERFACE mode
ip ospf cost
○ cost: The range is from 1 to 65535 (the default depends on the interface speed).
● Change the time interval the router waits before declaring a neighbor dead.
CONFIG-INTERFACE mode
ip ospf dead-interval seconds
648
Open Shortest Path First (OSPFv2 and OSPFv3)