BLADE OS™ Application Guide HP GbE2c Ethernet Blade Switch for c-Class BladeSystem Version 5.1 Advanced Functionality Software
Table Of Contents
- Contents
- Figures
- Tables
- Preface
- Part 1: Basic Switching
- Accessing the Switch
- The Management Network
- Local Management Using the Console Port
- The Command Line Interface
- Remote Management Access
- Client IP Address Agents
- Securing Access to the Switch
- Setting Allowable Source IP Address Ranges
- RADIUS Authentication and Authorization
- TACACS+ Authentication
- LDAP Authentication and Authorization
- Secure Shell and Secure Copy
- Configuring SSH/SCP Features on the Switch
- Configuring the SCP Administrator Password
- Using SSH and SCP Client Commands
- SSH and SCP Encryption of Management Messages
- Generating RSA Host and Server Keys for SSH Access
- SSH/SCP Integration with Radius Authentication
- SSH/SCP Integration with TACACS+ Authentication
- End User Access Control
- Ports and Trunking
- Port-Based Network Access Control
- VLANs
- Spanning Tree Protocol
- RSTP and MSTP
- Link Layer Discovery Protocol
- Quality of Service
- Accessing the Switch
- Part 2: IP Routing
- Basic IP Routing
- Routing Information Protocol
- IGMP
- OSPF
- OSPF Overview
- OSPF Implementation in BLADE OS
- OSPF Configuration Examples
- Remote Monitoring
- Part 3: High Availability Fundamentals
- High Availability
- Layer 2 Failover
- Server Link Failure Detection
- VRRP Overview
- Failover Methods
- BLADE OS Extensions to VRRP
- Virtual Router Deployment Considerations
- High Availability Configurations
- High Availability
- Part 4: Appendices
- Index
BLADE OS 5.1 Application Guide
BMD00113, September 2009 Chapter 12: OSPF 197
Defining Areas
If you are configuring multiple areas in your OSPF domain, one of the areas must be designated as
area 0, known as the backbone. The backbone is the central OSPF area and is usually physically
connected to all other areas. The areas inject routing information into the backbone which, in turn,
disseminates the information into other areas.
Since the backbone connects the areas in your network, it must be a contiguous area. If the
backbone is partitioned (possibly as a result of joining separate OSPF networks), parts of the AS
will be unreachable, and you will need to configure virtual links to reconnect the partitioned areas
(see “Virtual Links” on page 201).
Up to three OSPF areas can be connected to the GbE2c with BLADE OS software. To configure an
area, the OSPF number must be defined and then attached to a network interface on the switch. The
full process is explained in the following sections.
An OSPF area is defined by assigning two pieces of information—an area index and an area ID.
The command to define an OSPF area is as follows:
Note – The aindex option above is an arbitrary index used only on the switch and does not
represent the actual OSPF area number. The actual OSPF area number is defined in the areaid
portion of the command as explained in the following sections.
Assigning the Area Index
The aindex <area index> option is actually just an arbitrary index (0-2) used only by the GbE2c.
This index does not necessarily represent the OSPF area number, though for configuration
simplicity, it should where possible.
For example, both of the following sets of commands define OSPF area 0 (the backbone) and area 1
because that information is held in the area ID portion of the command. However, the first set of
commands is easier to maintain because the arbitrary area indexes agree with the area IDs:
Area index and area ID agree
/cfg/l3/ospf/aindex 0/areaid 0.0.0.0 (Use index 0 to set area 0 in ID octet format)
/cfg/l3/ospf/aindex 1/areaid 0.0.0.1 (Use index 1 to set area 1 in ID octet format)
Area index set to an arbitrary value
/cfg/l3/ospf/aindex 1/areaid 0.0.0.0 (Use index 1 to set area 0 in ID octet format)
/cfg/l3/ospf/aindex 2/areaid 0.0.0.1 (Use index 2 to set area 1 in ID octet format)
>> # /cfg/l3/ospf/aindex <area index>/areaid <n.n.n.n>