Administrator Guide

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
To confirm RFC 2328 flooding behavior, use the debug ip ospf packet command.
The following example shows no change in the updated packets (shown in bold). ACKs 2 (shown in bold) is printed only for ACK packets.
00:10:41 : OSPF(1000:00):
Rcv. v:2 t:5(LSAck) l:64 Acks 2 rid:2.2.2.2
aid:1500 chk:0xdbee aut:0 auk: keyid:0 from:Vl 1000
LSType:Type-5 AS External id:160.1.1.0 adv:6.1.0.0 seq:0x8000000c
LSType:Type-5 AS External id:160.1.2.0 adv:6.1.0.0 seq:0x8000000c
00:10:41 : OSPF(1000:00):
Rcv. v:2 t:5(LSAck) l:64 Acks 2 rid:2.2.2.2
aid:1500 chk:0xdbee aut:0 auk: keyid:0 from:Vl 100
LSType:Type-5 AS External id:160.1.1.0 adv:6.1.0.0 seq:0x8000000c
LSType:Type-5 AS External id:160.1.2.0 adv:6.1.0.0 seq:0x8000000c
00:10:41 : OSPF(1000:00):
Rcv. v:2 t:4(LSUpd) l:100 rid:6.1.0.0
aid:0 chk:0xccbd aut:0 auk: keyid:0 from:Te 10/21
Number of LSA:2
LSType:Type-5 AS External(5) Age:1 Seq:0x8000000c id:170.1.1.0 Adv:6.1.0.0
Netmask:255.255.255.0 fwd:0.0.0.0 E2, tos:0 metric:0
LSType:Type-5 AS External(5) Age:1 Seq:0x8000000c id:170.1.2.0 Adv:6.1.0.0
Netmask:255.255.255.0 fwd:0.0.0.0 E2, tos:0 metric:0
612
Open Shortest Path First (OSPFv2 and OSPFv3)