Configuring Routes

Configuring Routes of DSVPN

Context

The routes forwarded by a tunnel must be available on Spokes and the Hub so that packets encapsulated with mGRE can be forwarded correctly. These routes can be static routes or dynamic routes.

DSVPN supports the following route learning modes:

Route learning between Spokes (non-shortcut)

The next-hop address of the route from the source Spoke to the destination Spoke is the tunnel address of the destination Spoke, and each Spoke needs to learn the route to the remote end. This consumes many CPU and memory resources and requires large routing tables and high performance on Spokes. In practice, the Spokes have low performance and store a limited number of routes. The route learning solution applies to small- and medium-sized networks where there are fewer network nodes and a small number of routes.

mGRE tunnels between Spokes are set up in non-shortcut mode.
Spoke routes summarized to the Hub (shortcut mode)

The next-hop address of the route from the source Spoke to the destination Spoke is the tunnel address of the Hub, and Spokes only need to store routes to the Hub. The number of routes of Spokes is reduced, so the route learning solution applies to large-sized networks with many Spokes.

mGRE tunnels between Spokes are set up in shortcut mode.

Static routes and dynamic routing protocols can be deployed in the preceding two route learning modes. DSVPN supports OSPF and BGP.

Perform the following configurations on the Hub and Spokes.

Procedure

Configure a static route.
1. Run system-view
  The system view is displayed.
2. Run ip route-static ip-address { mask | mask-length } nexthop-address [ description text ]
  A static route is configured.
  - When Spokes learn routes from each other, the next-hop address of the static route from a Spoke to the Hub or another Spoke is the tunnel address of the remote device.
  - When routes of Spokes are summarized to the Hub, the next-hop address of the static route from a Spoke to the Hub or another Spoke is the tunnel address of the Hub.

Configuring a dynamic route

Run system-view
The system view is displayed.

Configure a dynamic route.

Dynamic routes can be implemented using OSPF, or BGP. For the configuration of a dynamic routing protocol, see Configuration Guide - IP Routing.

When configuring dynamic routing protocols, pay attention to the following points:

Scenario and Routing Protocol	OSPF	BGP
Non-Shortcut Scenario of DSVPN	Configure the OSPF network type to multicast using the ospf network-type broadcast command on the Hub and Spokes.	Route aggregation cannot be configured on the Hub.
Shortcut Scenario of DSVPN	Configure the OSPF network type to Point-to-Multipoint (P2MP) using the ospf network-type p2mp command on the Hub and Spokes.	Configure route aggregation on the Hub.