AZ-700 · Question #208
You have the on-premises networks shown in the following table. You have an Azure subscription that contains an Azure virtual WAN named VWAN1 and a virtual network named VNet1. VWAN is connected to…
The correct answer is D. the ExpressRoute connection to Branch3. Given the Virtual WAN routing preference is AS Path, traffic from VNet1 to 10.61.1.5 will use the ExpressRoute connection to Branch3 because it is the path with the shortest AS path for that destination.
Question
You have the on-premises networks shown in the following table. You have an Azure subscription that contains an Azure virtual WAN named VWAN1 and a virtual network named VNet1. VWAN is connected to the on-premises networks and VNet1 in a full mesh topology. The virtual hub routing preference for VWAN1 is AS Path. You need to route traffic from VNet1 to 10.61.1.5. Which path will be used?
Exhibit
Options
- Athe VPN connection to Branch1
- Bthe VPN connection to Branch2
- Cthe ExpressRoute connection to Branch2
- Dthe ExpressRoute connection to Branch3
How the community answered
(64 responses)- A9% (6)
- B5% (3)
- C2% (1)
- D84% (54)
Why each option
Given the Virtual WAN routing preference is AS Path, traffic from VNet1 to 10.61.1.5 will use the ExpressRoute connection to Branch3 because it is the path with the shortest AS path for that destination.
The VPN connection to Branch1 would only be chosen if it had the shortest AS path, which is unlikely compared to an ExpressRoute path under AS Path preference.
The VPN connection to Branch2 would only be chosen if it had the shortest AS path, which is unlikely compared to an ExpressRoute path under AS Path preference.
While ExpressRoute to Branch2 is an ExpressRoute path, the specific ExpressRoute from Branch3 is indicated as the correct answer, implying it has the shortest AS path among the ExpressRoute options or compared to VPNs.
Azure Virtual WAN, with a virtual hub routing preference set to AS Path, will select the path with the shortest BGP AS Path length when multiple connections advertise the same prefix. ExpressRoute connections typically have a shorter or more favorable AS path compared to VPN connections, making the ExpressRoute connection to Branch3 the preferred route for traffic to 10.61.1.5.
Concept tested: Virtual WAN routing preference (AS Path)
Source: https://learn.microsoft.com/en-us/azure/virtual-wan/virtual-wan-routing-about#routing-preference
Community Discussion
No community discussion yet for this question.