AZ-303 Exam - Question 185

Question

HOTSPOT -You have an Azure subscription named Subscription1. Subscription1 contains the virtual machines in the following table:Subscription1 contains a virtual network named VNet1 that has the subnets in the following table. VM3 has multiple network adapters, including a network adapter named NIC3. IP forwarding is enabled on NIC3. Routing is enabled on VM3. You create a route table named RT1 that contains the routers in the following table. You apply RT1 to Subnet1 and Subnet2. For each of the following statements, select Yes if the statement is true. Otherwise, select No. NOTE: Each correct selection is worth one point. Hot Area:.

Examice · Accepted Answer

IP forwarding enables the virtual machine a network interface is attached to:

✑ Receive network traffic not destined for one of the IP addresses assigned to any of the IP configurations assigned to the network interface.

✑ Send network traffic with a different source IP address than the one assigned to one of a network interface's IP configurations.

The setting must be enabled for every network interface that is attached to the virtual machine that receives traffic that the virtual machine needs to forward. A virtual machine can forward traffic whether it has multiple network interfaces or a single network interface attached to it.

Box 1: Yes -

The routing table allows connections from VM3 to VM1 and VM2. And as IP forwarding is enabled on VM3, VM3 can connect to VM1.

Box 2: No -

VM3, which has IP forwarding, must be turned on, in order for VM2 to connect to VM1.

Box 3: Yes -

The routing table allows connections from VM1 and VM2 to VM3. IP forwarding on VM3 allows VM1 to connect to VM2 via VM3.

References:

https://docs.microsoft.com/en-us/azure/virtual-network/virtual-networks-udr-overview https://www.quora.com/What-is-IP-forwarding

azurecert2021 · Answer

Given asnwer is correct due to following reason
 it allows connectivity from subnet 1 (10.0.1.0/24) and subnet 2(10.0.2.0/24) to VM3 so in other words VM1 and VM2 can establish connection with VM3 but it is vise versa hence vm3 can establish connectivity to vm1 and vm2.
 ideally NICs connected to subnets (same or different) within a VNet can communicate with each other without any extra configuration but when we define User define route(UDR) like here it take precedence over system routes

syu31svc · Answer

1. The routing table allows connections to VM3 from VM1 and VM2. And as IP forwarding is enabled on VM3, VM3 can connect to VM1.

2. VM3 must be turned on, in order for VM2 to connect to VM1.

3. The routing table allows connections from VM1 and VM2 to VM3. IP forwarding on VM3 allows VM1 to connect to VM2 via VM3.

https://docs.microsoft.com/en-us/azure/virtual-network/virtual-networks-udr-overview

Yes No Yes is the answer

TSMRE · Answer

On exam 6/7/21

atazlearner111 · Answer

I have a doubt here
would this create some kind of a loop ?

1. VM31 tries to reach VM2 
2. traffic gets redirected to VM3 as per route table - rule 2
3. VM3 forward the traffic to VM2 as per ip forwarding
4. On subnet2 the packets get redirected again to VM3 as per rule 2 in routing table attached to subnet2.

Can someone confirm this on Azure portal ?

nfett · Answer

repeat

edmacoar123 · Answer

On exam today 19/11/21. Correct answer. Score 860.

atazlearner111 · Answer

https://docs.microsoft.com/en-us/azure/virtual-network/virtual-networks-udr-overview

Deploy a virtual appliance into a different subnet than the resources that route through the virtual appliance are deployed in. Deploying the virtual appliance to the same subnet, then applying a route table to the subnet that routes traffic through the virtual appliance, can result in routing loops, where traffic never leaves the subnet.

sco_murad · Answer

Why do we need a routing appliance to route traffic between subnets within a single VNet?

Pinto · Answer

Repeat of Q72 in Topic 1 - https://www.examtopics.com/exams/microsoft/az-303/view/8/

SSANGKAL · Answer

Given answer seems to be correct, but...
How can VM1 and VM2 connect VM3 in the first place?

They are all in different subnet, and can't understand how 10.0.1.x & 10.0.2.x can initially connect 10.0.3.4 to have ip-forwarded.

leo_az300 · Answer

Doubt about Q2. In our env, we have vms in different subnets within one virtual network. 
no route table specification for those two subnet 
no 3rd vm/nic used as bridge with ip forward

connection between 2 vms are esatblished.

AZ-303 Exam - Question 185

Discussion