Users Guide

Fast Convergence (OSPFv2, IPv4 Only)
Fast convergence allows you to dene 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 dierent 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.
RFC-2328 Compliant OSPF Flooding
In OSPF, ooding is the most resource-consuming task. The ooding algorithm described in RFC 2328 requires that OSPF ood LSAs on all
interfaces, as governed by LSA’s ooding scope (refer to Section 13 of the RFC.)
When multiple direct links connect two routers, the RFC 2328 ooding algorithm generates signicant redundant information across all
links.
By default, Dell Networking OS implements an enhanced ooding procedure which dynamically and intelligently detects when to optimize
ooding. Wherever possible, the OSPF task attempts to reduce ooding overhead by selectively ooding on a subset of the interfaces
between two routers.
Enabling RFC-2328 Compliant OSPF Flooding
To enable OSPF ooding, use the following command.
When you enable this command, it congures Dell Networking OS to ood LSAs on all interfaces.
• Enable RFC 2328 ooding.
ROUTER OSPF mode
flood-2328
Example of Viewing the Debug Log for Flooding Behavior
To conrm RFC 2328 ooding behavior, use the debug ip ospf packet command. The following example shows no change in the
updated packets (shown in bold).
560
Open Shortest Path First (OSPFv2 and OSPFv3)