BLADE OS™ Application Guide HP GbE2c Ethernet Blade Switch for c-Class BladeSystem Version 5.1 Advanced Functionality Software

BLADE OS 5.1 Application Guide
198  Chapter 12: OSPF BMD00113, September 2009
Using the Area ID to Assign the OSPF Area Number
The OSPF area number is defined in the areaid <IP address> option. The octet format is used in
order to be compatible with two different systems of notation used by other OSPF network vendors.
There are two valid ways to designate an area ID:
 Placing the area number in the last octet (0.0.0.n)
Most common OSPF vendors express the area ID number as a single number. For example, the
Cisco IOS-based router command “network 1.1.1.0 0.0.0.255 area 1” defines the
area number simply as “area 1.” On the GbE2c, using the last octet in the area ID, “area 1”
is equivalent to “areaid 0.0.0.1”.
 Multi-octet (IP address)
Some OSPF vendors express the area ID number in multi-octet format. For example, “area
2.2.2.2” represents OSPF area 2 and can be specified directly on the GbE2c as
“areaid 2.2.2.2”.
Note – Although both types of area ID formats are supported, be sure that the area IDs are in the
same format throughout an area.
Attaching an Area to a Network
Once an OSPF area has been defined, it must be associated with a network. To attach the area to a
network, you must assign the OSPF area index to an IP interface that participates in the area. The
format for the command is as follows:
For example, the following commands could be used to configure IP interface 14 for a presence on
the 10.10.10.1/24 network, to define OSPF area 1, and to attach the area to the network:
>> # /cfg/l3/ospf/if <interface number>/aindex <area index>
>> # /cfg/l3/if 14 (Select menu for IP interface 14)
>> IP Interface 14# addr 10.10.10.1 (Define IP address on backbone network)
>> IP Interface 14# mask 255.255.255.0 (Define IP mask on backbone)
>> IP Interface 14# ena (Enable IP interface 14)
>> IP Interface 14# ../ospf/aindex 1
(Select menu for area index 1)
>> OSPF Area (index) 1 # areaid 0.0.0.1
(Define area ID as OSPF area 1)
>> OSPF Area (index) 1 # ena (Enable area index 1)
>> OSPF Area (index) 1 # ../if 14 (Select OSPF menu for interface 14)
>> OSPF Interface 14# aindex 1 (Attach area to network on interface 14)
>> OSPF Interface 14# enable (Enable interface 14 for area index 1)