Dell Force10 MXL Blade MXL 10/40GbE Switch IO Module Configuration Guide - Page 365

Fast Convergence (OSPFv2, IPv4 only), Multi-Process OSPF (OSPFv2

Page 365 highlights

• Opaque Link-local (type 9) 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. FTOS 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 OSPF (OSPFv2, IPv4 only) Multi-process OSPF is supported on OSPFv2 with IPv4 only. 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. • The MXL Switch supports up to 16 OSPFv2 processes. Each OSPFv2 process has a unique process ID and must have an associated router ID. There must be an equal number of interfaces in Layer-3 mode for the number of processes created. For example, if five OSPFv2 processes are created 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 SNMP requests and send SNMP traps. The mib-binding command identifies one of the OSPVFv2 processes as the process responsible for SNMP management. If the mib-binding command is not specified, 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, FTOS 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. Open Shortest Path First (OSPFv2) | 363

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Open Shortest Path First (OSPFv2)
|
363
Opaque Link-local (type 9)
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. FTOS allows you to accept and originate LSAs as soon as they are
available to speed up route information propagation.
Multi-Process OSPF (OSPFv2, IPv4 only)
Multi-process OSPF is supported on OSPFv2 with IPv4 only.
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.
The MXL Switch supports up to 16 OSPFv2 processes.
Each OSPFv2 process has a unique process ID and must have an associated router ID. There must be an
equal number of interfaces in Layer-3 mode for the number of processes created. For example, if five
OSPFv2 processes are created 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 SNMP requests and
send SNMP traps. The
mib-binding
command identifies one of the OSPVFv2 processes as the process
responsible for SNMP management. If the
mib-binding
command is not specified, 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, FTOS 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.
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.