nx.os.and.cisco.nexus.switching.2nd.edition.1587143046

(IETF) Requests for Comments (RFCs). OSPF uses the concept of areas to provide
scalability and administrative control for IP routes. Following are three versions of OSPF:
• OSPFv1, which has been replaced by OSPFv2
• OSPFv2, which routes IPv4
• OSPFv3, which introduces significant changes to OSPFv2 and is designed to route
IPv6
OSPF is supported on both the Nexus 7000 and 5500 series switches. The Nexus 5500
series switches must be configured with a Layer 3 daughtercard or module, dependent on the
specific platform. The Nexus 5500 series also requires an Enterprise License for full OSPF
functionality. (The Base license is limited to 256 OSPF dynamically learned routes.) The
examples in this chapter focus on OSPF configuration for the Nexus 7000.
OSPFv2 Configuration
OSPF within NX-OS is compatible with OSPF on IOS and other IETF-compliant devices
enabling a smooth integration of Nexus equipment. Configuring OSPF within NX-OS will be
similar, yet distinctly different in some aspects to traditional IOS configuration. These
differences will be highlighted throughout the section.
Enabling OSPF is a multistep process that is covered in detail. The following is a quick
listing of steps to enable a basic configuration of OSPF:
1. Enable OSPF.
2. Configure the OSPF routing process.
3. Assign interfaces to the OSPF instance.
4. Configure passive-interfaces if necessary.
5. Configure network summarization.
6. Configure redistribution of other protocols if necessary.
7. Verify the OSPF operation.
The first step to configure OSPF is to enable it in global configuration mode using the
feature command, as shown in Example 3-31. With the modular nature of NX-OS, using the
feature command loads the OSPF modular code into memory for execution. Without the
feature enabled, it would not be resident in memory. Figure 3-5 illustrates the topology used
in Example 3-32 through 3-41.