White Papers

○ For a VLAN interface, enter the keyword vlan then a number from 1 to 4094 (for example, passive-interface vlan
2222 ).
The keyword default sets all interfaces on this OSPF process as passive.
To remove the passive interface from select interfaces, use the no passive-interface interface command while
passive interface default is configured.
To enable both receiving and sending routing updates, use the no passive-interface interface command.
When you configure a passive interface, the show ip ospf process-id interface command adds the words passive
interface to indicate that the hello packets are not transmitted on that interface (shown in bold).
Enabling Fast-Convergence
The fast-convergence CLI sets the minimum origination and arrival LSA parameters to zero (0), allowing rapid route calculation.
When you disable fast-convergence, origination and arrival LSA parameters are set to 5 seconds and 1 second, respectively.
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).
DellEMC(conf-router_ospf-1)#fast-converge 2
DellEMC(conf-router_ospf-1)#ex
DellEMC(conf)#ex
DellEMC#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
DellEMC#
The following examples shows how to disable fast-convergence.
DellEMC#(conf-router_ospf-1)#no fast-converge
DellEMC#(conf-router_ospf-1)#ex
DellEMC#(conf)#ex
DellEMC##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
DellEMC#
572
Open Shortest Path First (OSPFv2 and OSPFv3)