Dell C1048P Port Extender Networking Configuration Guide for the C9000 Series - Page 627

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. The system 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 (IPv4 only) Multi-process OSPF is supported only on OSPFv2 with IPv4 on the switch. Up to 32 OSPFv2 processes are 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 Though there are may be several OSPFv2 processes, only one process can process simple network management protocol (SNMP) requests and send SNMP traps. The mib-binding command identifies one of the OSPVFv2 processes as the process responsible for SNMP management. If you do not specify the mib-binding command, the first OSPFv2 process created manages the SNMP processes and traps. RFC-2328 Compliant OSPF Flooding In OSPF, flooding is the most resource-consuming task. The flooding algorithm described in RFC 2328 requires that OSPF flood LSAs on all interfaces, as governed by LSA's flooding scope (refer to Section 13 of the RFC.) When multiple direct links connect two routers, the RFC 2328 flooding algorithm generates significant redundant information across all links. By default, the system implements an enhanced flooding procedure which dynamically and intelligently detects when to optimize flooding. Wherever possible, the OSPF task attempts to reduce flooding overhead by selectively flooding on a subset of the interfaces between two routers. Enabling RFC-2328 Compliant OSPF Flooding To enable OSPF flooding, use the following command. When you enable this command, it configures the system to flood LSAs on all interfaces. • Enable RFC 2328 flooding. ROUTER OSPF mode flood-2328 Examples of OSPF Flooding Behavior To confirm RFC 2328 flooding behavior, use the debug ip ospf packet command. Open Shortest Path First (OSPFv2 and OSPFv3) 627