Users Guide

An unplanned restart occurs when an unplanned event causes the active RPM to switch to the backup RPM, such as when
an active process crashes, the active RPM is removed, or a power failure happens. During an unplanned restart, OSPF sends
out a Grace LSA when the backup RPM comes online.
To display the configuration values for OSPF graceful restart, enter the show run ospf command for OSPFv2 and the show
run ospf and show ipv6 ospf database database-summary commands for OSPFv3.
Fast Convergence (OSPFv2, IPv4 Only)
Fast convergence allows you to define the speeds at which LSAs are originated and accepted, and reduce OSPFv2 end-to-end
convergence time.
Dell 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 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 Networking and Cisco routers, the hello interval and dead interval must be the
same on both routers.
In Dell 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 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.
Open Shortest Path First (OSPFv2 and OSPFv3) 531