Product Documentation

Dynamic routing

After configuration and deployment of SD-WAN, appliances in the network and once the connections are established it is important to ensure that the traffic is properly redirected through the overlay SD-WAN network. You can check traffic redirection by using ping and traceroute diagnostic tools. If the ping and traceroute tests indicate that connectivity is established through the underlay paths, traffic redirection can be achieved by using the following dynamic routing protocols.

  • Open Shortest Path First (OSPF): It is an interior gateway protocol, used to redirect traffic within an autonomous system, like the enterprise network. OSPF uses a link state routing algorithm to detect changes in the network topology and reroute packets by computing the shortest path free for each route. Use this protocol to redirect MPLS traffic. For more information, see Configure OSPF section.

  • Border Gateway Protocol (BGP): It is an exterior gateway protocol designed to redirect traffic routing and reachability information among different autonomous systems on the internet. It is capable of making routing decisions based on paths determined by ISPs. Use this protocol to redirect Internet traffic. For more information, see Configure BGP section.

Configure OSPF

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OSPF basic settings

Here are the parameters to be configured:

  • Enable: Allow the OSPF routing protocol on SD-WAN appliance to start exchanging Hello packets between neighboring routers.

  • Router ID: An IPv4 address, used for OSPF advertisements. This is optional, if not specified the lowest virtual IP of the virtual interfaces participating in routing is chosen.

  • Export OSPF Route Type: Advertise the SD-WAN route to OSPF neighbors as type 1 Intra-area route or type 5 External route.

  • Export OSPF Route Weight: The cost advertised to OSPF neighbors is the original route cost and the weight configured here.

  • Advertise SD-WAN Routes: To advertise SD-WAN routes to the peer network elements.

  • Advertise BGP Routes: To enable redistribution of BGP routes into the OSPF domain.

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Areas

Provide the Area ID of the network that OSPF will learn routes from and advertise routes. Stub area ensures that this area will not receive route advertisements from outside of the designated Autonomous System. Configure the virtual interface settings.

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Configure BGP

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BGP basic settings

Here are the parameters to be configured:

  • Enable: Allow the BGP routing protocol on SD-WAN appliance to start sending an open message as part of BGP peering.

  • Router ID: IPv4 address used for BGP advertisements. This is optional, if not specified the lowest virtual IP of the virtual interfaces participating in routing is chosen.

  • Local Autonomous System: Autonomous system number the BGP protocol is running in.

  • Advertise SD-WAN Routes: To advertise SD-WAN routes to the peer network elements.

  • Advertise BGP Routes: To enable redistribution of OSPF routes into BGP domain.

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Add communities

A collection of BGP communities that can be used for route filtering. The community list can also be used to set or modify the communities of a matching route.

For each policy, users can configure multiple community strings, AS-PATH-PREPEND, MED attribute. Users can configure up to 10 attributes for each policy.

Specify the name for the community and enter a community string to be advertised.

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Configure BGP policies

A collection of BGP attributes which can be used to set or modify route attributes for each BGP Peer. Create BGP policies to be applied selectively to a set of networks on a per-neighbor basis, in either direction (import or export). An SD-WAN appliance supports eight policies per site, with up to eight network objects (or eight networks) associated with a policy.

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Add neighbors

Neighbors are all of the configured BGP peer routers that are checked to find the shortest paths for routing. All the neighbors must be part of the same Autonomous System.

You can add a configured BGP policy for neighboring routers. You can specify the direction to indicate if this policy is applied for incoming or outgoing routes.

Import filters

You can configure Filters to fine-tune how route-learning takes place.

Import filter rules are rules that have to be meet before importing dynamic routes into the SD-WAN route database. By default, no routes are imported.

Click Add Import Rule.

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Export filters

Define the rules that have to meet when advertising SD-WAN routes over dynamic routing protocols. By default, all routes are advertised to peers.

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Dynamic routing

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