Concept Guide
Fast Convergence (OSPFv2, IPv4 Only)
Fast convergence allows you to dene the speeds at which LSAs are originated and accepted, and reduce OSPFv2 end-to-end
convergence time.
Dell EMC Networking OS allows you to accept and originate LSAs as soon as they are available to speed up route information propagation.
NOTE: The faster the convergence, the more frequent the route calculations and updates. This impacts CPU utilization and may
impact adjacency stability in larger topologies.
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 dierent 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 ve OSPFv2 processes on a system, there must be at least
ve 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 eld in the OspfNbrTable returns a value of 66.
OSPF ACK Packing
The OSPF ACK packing feature bundles multiple LS acknowledgements in a single packet, signicantly 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-congurable.
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.
Conguring 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 conguration.
INTERFACE mode
ip ospf dead-interval <x>
Open Shortest Path First (OSPFv2 and OSPFv3)
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