Configuring the Open Shortest Path First Protocol
20-15
20
• OSPFv2 is a compatible upgrade to OSPF. It involves enhancements to protocol
message authentication, and the addition of a point-to-multipoint interface which
allows OSPF to run over non-broadcast networks, as well as support for
overlapping area ranges.
• When using OSPF, you must organize your network (i.e., autonomous system) into
normal, stub, or not-so-stubby areas; configure the ranges of subnet addresses
that can be aggregated by link state advertisements; and configure virtual links for
areas that do not have direct physical access to the OSFP backbone.
- To implement OSPF for a large network, you must first organize the network into
logical areas to limit the number of OSPF routers that actively exchange Link
State Advertisements (LSAs). You can then define an OSPF interface by
assigning an IP interface configured on this router to one of these areas. This
OSPF interface will send and receive OSPF traffic to neighboring OSPF routers.
- You can further optimize the exchange of OSPF traffic by specifying an area
range that covers a large number of subnetwork addresses. This is an important
technique for limiting the amount of traffic exchanged between Area Border
Routers (ABRs).
- And finally, you must specify a virtual link to any OSPF area that is not physically
attached to the OSPF backbone. Virtual links can also be used to provide a
redundant link between contiguous areas to prevent areas from being
partitioned, or to merge backbone areas. (Note that virtual links are not
supported for stubs or NSSAs.)
Configuring General Protocol Settings
To implement dynamic OSPF routing, first assign VLAN groups to each IP subnet to
which this router will be attached, then use the OSPF / General Configuration menu
to enable OSPF, assign an Router ID to this device, and set the other basic protocol
parameters.
Command Attributes
General Information –
•
OSPF Routing Process
– Enables or disables OSPF routing for all IP interfaces
on the router. (Default: Disabled)
•
OSPF Router ID
– Assigns a unique router ID for this device within the
autonomous system. (Default: The lowest interface address)
The router ID must be unique for every router in the autonomous system. Using the
default setting based on the highest interface address ensures that each router ID
is unique. Also, note that the router ID cannot be set to 0.0.0.0 or 255.255.255.255.
If this router already has registered neighbors, the new router ID will be used when
the router is rebooted, or manually restarted using the
no router ospf
command
followed by the
router ospf
command.
•
Version Number
21
– The OSPF version number. The OSPF protocol
implemented in this device is based on RFC 2328 (Version 2). It also supports RFC
1583 (early Version 2) compatibility mode.
21. These items are read only.
Summary of Contents for 8926EM
Page 6: ...ii ...
Page 34: ...Getting Started ...
Page 44: ...Introduction 1 10 1 ...
Page 62: ...Initial Configuration 2 18 2 ...
Page 64: ...Switch Management ...
Page 76: ...Configuring the Switch 3 12 3 ...
Page 118: ...Basic Management Tasks 4 42 4 ...
Page 164: ...User Authentication 6 28 6 ...
Page 176: ...Access Control Lists 7 12 7 ...
Page 284: ...Quality of Service 14 8 14 ...
Page 294: ...Multicast Filtering 15 10 15 ...
Page 300: ...Domain Name Service 16 6 16 ...
Page 310: ...Dynamic Host Configuration Protocol 17 10 17 ...
Page 320: ...Configuring Router Redundancy 18 10 18 ...
Page 344: ...IP Routing 19 24 19 ...
Page 356: ...Unicast Routing 20 12 20 Web Click Routing Protocol RIP Statistics Figure 20 5 RIP Statistics ...
Page 386: ...Unicast Routing 20 42 20 ...
Page 388: ...Command Line Interface ...
Page 400: ...Overview of the Command Line Interface 21 12 21 ...
Page 466: ...SNMP Commands 24 16 24 ...
Page 520: ...Access Control List Commands 26 18 26 ...
Page 546: ...Rate Limit Commands 30 2 30 ...
Page 612: ...VLAN Commands 34 24 34 ...
Page 626: ...Class of Service Commands 35 14 35 ...
Page 670: ...DHCP Commands 39 16 39 ...
Page 716: ...IP Interface Commands 41 36 41 ...
Page 768: ...IP Routing Commands 42 52 42 ...
Page 770: ...Appendices ...
Page 791: ......