The edge gateway supports OSPF, an interior gateway protocol that routes IP packets only within a single routing domain. Configure OSPF in vCloud Air to exchange routing information between edge gateways in vCloud Air.

Use OSPF to gather link state information from available routers and construct a topology map of the network. The topology determines the routing table presented to the Internet layer, which makes routing decisions based on the destination IP address found in IP packets.

OSPF routing policies provide a dynamic process of traffic load balancing between routes of equal cost. An OSPF network is divided into routing areas to optimize traffic flow and limit the size of routing tables. An area is a logical collection of OSPF networks, routers, and links that have the same area identification. Areas are identified by an Area ID.

A Router ID must have been selected. Specify Global Configuration

1

Log in to vCloud Air and navigate to the vCloud Edge Gateway Services UI.

See Log In and Navigate to Advanced Networking Services for information.

2

Click the Routing tab and OSPF.

3

In OSPF Configuration, complete the OSPF options:

a

Click Edit next to OSPF Configuration.

b

Select Enable OSPF.

c

For packet forwarding to be uninterrupted during restart of OSPF services, select Enable Graceful Restart.

d

To allow the edge gateway to advertise itself as a default gateway to its peers, select Enable Default Originate.

e

Click OK.

4

In Area Definitions, configure the OSPF areas:

a

Delete the not-so-stubby area (NSSA) 51 that is configured by default.

b

Click the Add (add icon) icon.

c

Type an area ID.

The edge gateway supports an area ID in the form of an IP address or decimal number.

d

In Type, select Normal or NSSA.

NSSAs prevent the flooding of AS-external link-state advertisements (LSAs) into NSSAs. They rely on default routing to external destinations. Hence, NSSAs must be placed at the edge of an OSPF routing domain. NSSA can import external routes into the OSPF routing domain, thereby providing transit service to small routing domains that are not part of the OSPF routing domain.

e

Required In Authentication, select Password or MD5 and type the password or MD5 key, respectively, for the value.

Password: In this method of authentication, a password is included in the transmitted packet.

MD5: This authentication method uses MD5 (Message Digest type 5 ) encryption. An MD5 checksum is included in the transmitted packet.

5

In Area to Interface Mapping, map interfaces to areas by completing the following steps:

a

In Area Definitions, click the Add (add icon) icon.

b

From the vNIC drop-down list, select the interface that you want to map to the OSPF area. The interface specifies the external network that both edge gateways are connected to.

c

Type an Area ID. The edge gateway supports an area ID in the form of an IP address or decimal number.

d

(Optional) Select Ignore Interface MTU Settings to disable MTU mismatch detection on received Database Descriptor (DBD) packets.

When configuring OSPF, routers connected to the same shared subnet should have the same MTU setting. However, you can force OSPF neighbors to establish a session even when their interface MTU settings do not match. Use caution when selecting this setting because it can lead to packet drops and cause the adjacency to reset repeatedly.

e

(Optional) Expand the Advanced section and complete the following options.

Note

vCloud Air provides a default value for each option. You can accept these default values or edit them for your environment.

Option

Description

Hello Interval

Specifies the default interval between hello packets that are sent on the interface.

Dead Interval

Specifies the default interval during which at least one hello packet must be received from a neighbor before the router declares that neighbor down.

Priority

Specifies the default priority of the interface. The interface with the highest priority is the designated router.

Cost

Specifies the default overhead required to send packets across that interface. The cost of an interface is inversely proportional to the bandwidth of that interface. The larger the bandwidth, the smaller the cost.

6

Click Publish Changes.

Add a firewall rule that allows traffic between the edge gateways in vCloud Air that you are configuring OSPF routing for. See Add an Edge Gateway Firewall Rule for information.

Configure OSPF on the other edge gateways in vCloud Air that you want to exchange routing information with.