Concept Guide

Multi-Process OSPFv2 with VRF
Multi-process OSPF with VRF is supported on the Dell EMC Networking OS. Only one OSPFv2 process per VRF is supported.
Multi-process OSPF allows multiple OSPFv2 processes on a single router. Multiple OSPFv2 processes allow for isolating
routing domains, supporting multiple route policies and priorities in different domains, and creating smaller domains for easier
management. Each OSPFv2 process has a unique process ID and must have an associated router ID. There must be an equal
number of interfaces and must be in Layer-3 mode for the number of processes created. For example, if you create five OSPFv2
processes on a system, there must be at least five interfaces assigned in Layer 3 mode. Each OSPFv2 process is independent. If
one process loses adjacency, the other processes continue to function.
Processing SNMP and Sending SNMP Traps
Only the process in default vrf can process the SNMP requests and send SNMP traps.
NOTE: SNMP gets request corresponding to the OspfNbrOption field in the OspfNbrTable returns a value of 66.
OSPF ACK Packing
The OSPF ACK packing feature bundles multiple LS acknowledgements in a single packet, significantly reducing the number of
ACK packets transmitted when the number of LSAs increases.
This feature also enhances network utilization and reduces the number of small ACK packets sent to a neighboring router. OSPF
ACK packing is enabled by default and non-configurable.
Setting OSPF Adjacency with Cisco Routers
To establish an OSPF adjacency between Dell EMC Networking and Cisco routers, the hello interval and dead interval must be
the same on both routers.
In Dell EMC Networking OS, the OSPF dead interval value is, by default, set to 40 seconds, and is independent of the OSPF
hello interval. Configuring a hello interval does not change the dead interval in Dell EMC Networking OS. In contrast, the OSPF
dead interval on a Cisco router is, by default, four times as long as the hello interval. Changing the hello interval on the Cisco
router automatically changes the dead interval.
To ensure equal intervals between the routers, use the following command.
● Manually set the dead interval of the Dell EMC Networking router to match the Cisco configuration.
INTERFACE mode
ip ospf dead-interval <x>
In the following example, the dead interval is set at 4x the hello interval (shown in bold).
DellEMC(conf)#int gigabitethernet 2/2
DellEMC(conf-if-gi-2/2)#ip ospf hello-interval 20
DellEMC(conf-if-gi-2/2)#ip ospf dead-interval 80
DellEMC(conf-if-gi-2/2)#
In the following example, the dead interval is set at 4x the hello interval (shown in bold).
DellEMC(conf-if-gi-2/2)#ip ospf dead-interval 20
DellEMC(conf-if-gi-2/2)#do show ip os int gigabitethernet 1/3
GigabitEthernet 2/2 is up, line protocol is up
Internet Address 20.0.0.1/24, Area 0
Process ID 10, Router ID 1.1.1.2, Network Type BROADCAST, Cost: 1
Transmit Delay is 1 sec, State DR, Priority 1
Designated Router (ID) 1.1.1.2, Interface address 30.0.0.1
Backup Designated Router (ID) 1.1.1.1, Interface address 30.0.0.2
Timer intervals configured, Hello 20, Dead 80, Wait 20, Retransmit 5
Hello due in 00:00:04
Neighbor Count is 1, Adjacent neighbor count is 1
Open Shortest Path First (OSPFv2 and OSPFv3)
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