Question 375 - 300-415 discussion

To establish a strict hub-and-spoke topology in Cisco SD-WAN for a specific VPN, such as VPN2, a control policy must be configured. This control policy dictates how traffic flows between sites, ensuring that all branch traffic is routed through the hub site.

1.Control Policy Components:

oSite Lists: Define which sites are considered hubs and which are branches.

oVPN Lists: Identify the VPNs to which the policy applies.

oControl Policy: Use sequences to match routes and specify actions to accept or reject traffic based on the defined topology.

1.Policy Analysis:

oOption A: Correctly defines site lists for hub sites (site-id 1-2) and creates a control policy that matches routes for VPN2, accepting routes from hub sites and rejecting routes from others. This ensures that traffic from branches (other sites) is only accepted if it routes through the hubs.

oOther options either incorrectly define the site lists or do not properly match and set the routes to enforce the strict hub-and-spoke topology.

1.Policy Configuration:

policy

lists

vpn-list VPN2

vpn 2

site-list hub_sites

site-id 1-2

!

control-policy vpn_multi_topology

sequence 10

match route

site-list hub_sites

vpn-list VPN2

!

action accept

!

sequence 20

match route

vpn-list VPN2

!

action reject

!

default-action accept

1.Reference:

oCisco SD-WAN Control Policy Configuration Guide

oCisco SD-WAN Hub-and-Spoke Topology Deployment Guide