Document toolboxDocument toolbox

Configuring OSPF Routing Protocol

Owned by Shirly Tsang
Last updated: Sept 06, 2024 by Sri Raghu
4 min read

 Use the Routing Protocol step of the Create OSPF Protocol Settings wizard to configure the OSPF settings and set up a service instance. Specify the following:

OSPF Enabled: Use the toggle switch to enable or disable the OSPF service.

IPv4 Prefix List

When you configure an IPv4 prefix list, you filter OSPF routes by assigning the prefix list to a neighbor rather than by using an autonomous system (AS) path filter. The process for evaluating a prefix against a prefix list ends when a match is found. For example, to disallow redistribution of a route for 10.0.0.0/24 through OSPF, define an IPv4 prefix list that includes this prefix; the system will reference it from the OSPF redistribution route map.

To create an IPv4 prefix list, click Add and specify the following:

  • Name: Enter the name of the prefix list. Create a name that does not exceed 64 characters. Use numbers, any special characters, uppercase and lowercase letters, and even spaces. Start and end a name with any character other than a space. Leading and trailing spaces will be trimmed off automatically.

  • Description: Enter the description for the IPv4 prefix list.

  • IPv4 Prefix List: Click Add and specify the following:

    • ACTION: Choose the action you want to apply to this IPv4 prefix list. You can either allow or deny traffic to the route that matches the prefix list.

    • PREFIX: Enter the IPv4 prefix. For example, if you want to permit or deny traffic to 10.0.0.0/8, enter 10.0.0.0/8 here.

    • PREFIX LENGTH GE: This item specifies the prefix length that is greater than or equal to the subnet’s value. This is the lowest value of the range of prefix lengths.

    • IPV4 PREFIX LENGTH LE: This item specifies the prefix length that is less than or equal to the subnet’s value. This is the highest value of the range of prefix lengths.

    • SEQUENCE: To specify the entry point of this IPv4 prefix list among other OSPF configurations, enter a number from 1 to 2147483646. For example, if you configure ACTION = Permit, IPv4 PREFIX = 10.0.0.0/8, and IPv4 PREFIX LENGTH LESS OR EQUAL = 19, then all networks that fall within the 10.0.0.0/8 range AND have a subnet mask of /19 or less will be allowed through OSPF.

To add the prefix list, click Add.

Route Map

A route map evaluates the matching conditions until a successful match occurs. After the match occurs, the route map stops evaluating the matching conditions and starts executing the conditions in the order in which they were configured. If a successful match does not occur, the route map “falls through” and evaluates the next sequence number until all configured route map entries have been evaluated or a successful match has occurred. To identify an entry, each route map sequence is tagged with a sequence number. Route map entries are evaluated from the lowest sequence number to the highest sequence number. 

To create a route map, click Add and specify the following:

  • Name: Enter the name of the route map.

  • Action: The action configured for the route map rule. This can be DENY or PERMIT.

  • Description: Enter the description for the route map.

  • Sequence: The route map sequence indicates the position of a new route map in the list of route maps already configured using the same name. The range of the sequence number is from 1 to 10.

  • Match Conditions: Click Add and specify the following in the table:

    • Condition: From the drop-down list, choose the condition to be matched.

    • Condition Value: From the drop-down list, choose the value to be matched.

  • Set Community: This sets the OSPF community for a route matched by the route map. Click Add and specify the following in the table:

    • Community: Enter the community number to use. This is either a number from 1 to 4,294,967,200 or the predefined communities of no-export or no-advertise.

    • Description: Enter the description for this community.

To save the configuration, click Add.

OSPF Config

Expand the Address Family IPv4 Unicast section, and do the following:

  • Expand the Areas section, and click Add to add an IP address as an area.

    • AREA: As the area ID, enter an integer in the range of 0 to 4294967295. An area is a collection of subdomains, networks, or routers, and it is identified with a unique ID. In OSPF, Area 0 is created by default and is called the backbone area. In Service Edge, a router corresponds to a Service Edge instance and an area comprises multiple Service Edge instances.

    • AUTH TYPE: Choose Simple or Message Digest. 

  • Auto-cost reference bandwidth: 

    • Expand the Default Info Originate section, and specify the following:

      • Advertise Default Route: Enable this to advertise the default route. Set the toggle to True or False.

      • Always: Set the toggle to True or False. 

      • Metric: 

      • Metric Type: Choose 1 or 2. 

      • Route Map: 

        • Expand the Global section. In the Router ID field, enter the IP address of the Service Edge instances.

      • Log Adjacency Changes: Set the toggle to True or False. 

      • Passive All: Set the toggle to True or False. 

        • Expand the Passive Interfaces section, and click Add. 

          • PASSIVE INTERFACE: 

            • In PID, enter a random number as the OSPF process ID. The PID is also called the instance ID and is local to OSPF. Service Edge supports only one instance of OSPF.

            • Expand the Interfaces section, and select the area PID that you entered in the Global section. In the Interface field, enter a name for the area interface.

To save the configuration, click Add. To view the Service Configuration Summary, click Next.