An administrator designs a virtual network named `vnet-corp-ops` with the address space 19… — Microsoft Azure Solutions Architect (AZ-305)

An administrator designs a virtual network named `vnet-corp-ops` with the address space $192.168.0.0/16$ . The virtual network contains a subnet named `snet-application` ( $192.168.1.0/24$ ) and a security subnet named `snet-security` ( $192.168.2.0/24$ ). A network virtual appliance (NVA) is deployed in `snet-security` with the IP address $192.168.2.4$ .

To inspect internal traffic, the administrator creates a route table and associates it with `snet-application`. The route table contains a user-defined route for the prefix $192.168.0.0/16$ with a next hop type of Virtual Appliance and the next hop IP address set to $192.168.2.4$ .

How will Azure route traffic sent from a virtual machine in `snet-application` to a destination IP address of $192.168.3.10$ ?

The traffic is forwarded to the network virtual appliance at $192.168.2.4$ .Answer
B
The traffic is routed directly to $192.168.3.10$ because default system routes for local virtual network traffic take precedence over user-defined routes.
C
The traffic is dropped by Azure because forwarding traffic back into the virtual network via a custom route is blocked by default.
D
The traffic is routed directly to $192.168.3.10$ because the system route is considered a more specific match than the user-defined route.

Answer

The traffic is forwarded to the network virtual appliance at

192.168.2.4

The correct answer is correct because Azure routing rules dictate that when two routes have the same prefix length, a user-defined route takes precedence over the default system route. Therefore, the custom route directing traffic to the virtual appliance at

192.168.2.4

is selected.

Step-by-Step Solution

Identify the destination IP and find all matching routes in the route table associated with snet-application.

The destination IP

192.168.3.10

matches both the default system route for the virtual network (

192.168.0.0/16

) and the user-defined route (

192.168.0.0/16

Azure evaluates routes by comparing the destination IP against the prefixes of all active routes.

Apply the longest prefix match rule to determine if one route is more specific.

Both matching routes have the same prefix length of

/16

If one route had a longer prefix, it would be selected immediately. Since they are identical, prefix length does not break the tie.

Apply Azure route source priority rules to resolve identical prefix matches.

The user-defined route is selected over the default system route.

Azure assigns higher priority to user-defined routes than to default system routes when prefix lengths are identical.

Key Concept

User-defined route precedence over default system routes

Question

Answer

Step-by-Step Solution

Key Concept

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