Exam AZ-104 topic 5 question 93 discussion

Hi Admin, This looks like incomplete question or something is missing. Could you please correct this and add more discussion?

CORRECT ANSWER YES NO YES YES -For VM1,server1.contoso.com resolves to 131.107.3.3 VM1 is connected to VNET1 which has Default(Azure-Provided) DNS Server and linked to Azure Private DNS Server contoso.com (131.107.3.3 and 131.107.3.4 DNS Servers). That means VM1 has these 2 DNS servers for resloving. DNS Servers for VNET1 server1.contoso.com = 131.107.3.3 server2.contoso.com = 131.107.3.4 NO-For VM2,server1.contoso.com resolves to 131.107.3.3 VM2 belongs to VNET2 has Custom DNS:192.168.0.5 IP of VM4 ( not takes from dedault Azure: the server1.contoso.com = 131.107.3.4 and server2.contoso.com = 131.107.3.4) -NO VM2 will resolve from VM4 (DNS Server1.contoso.com=131.107.2.3 and Server2.contoso.com=131.107.2.4) YES- For VM3,server2.contoso.com resolves to 131.107.2.4 VM3 belongs to VNET3 has Custom DNS:192.168.0.5 IP of VM4 ( not takes from default Azure: the server1.contoso.com = 131.107.3.4 and server2.contoso.com = 131.107.3.4) VM3 will resolve from VM4 (DNS Server1.contoso.com=131.107.2.3 and Server2.contoso.com=131.107.2.4)

YNN You are assuming that VM4 has DNS Role and it has the "contoso.com" zone, they are not saying nothing about this.

Yes Yes Yes

Yes Yes No We have two DNS service providers here: 1-Private DNS has (server1.contoso.com & server2.contoso.com) and linked to VNET1 and VNET2, 2- Local DNS on VM4 in VNET3, that has no records in the provided exhibit YES: VM1 in Vnet1: resolve DNS names of server1 through the "private DNS" which has it's IP YES: VM2 in Vnet2: resolve DNS names of server1 through the "private DNS" which has it's IP NO: VM3 in Vnet3: CAN'T resolve DNS names of server2 through the "private DNS" , cause it will talk to DNS service on VM4 which has no record for the requested server

YNN VM2 and VM3 are both using the same DNS, and that DNS server is in VNET3 that cannot resolve the private DNS zone.

Fudge this, I think its YYN Any solid answer here?

Agree with Y,Y,Y and best explained by Trevor_VT See; https://learn.microsoft.com/en-us/azure/dns/private-dns-virtual-network-links "If you choose to link your virtual network with the private DNS zone without autoregistration, the virtual network is treated as a resolution virtual network only. DNS records for virtual machines deployed this virtual network won't be created automatically in the private zone. However, virtual machines deployed in the virtual network can successfully query for DNS records in the private zone. These records include manually created and auto registered records from other virtual networks linked to the private DNS zone. One private DNS zone can have multiple resolution virtual networks and a virtual network can have multiple resolution zones associated to it."

Two Observations from given information: - [ ] VNET1 has default DNS server so it will be resolved by the private zone. - [ ] VNET2 and VNET3 has DNS servers listed to IP address of VM4, which is in VNET3. So VMs on VNET2 and VNET3 will be resolved by the DNS server in VM4. Based on those observations: - [ ] Yes - Is VM1 resolved by private zone? Yes. So it resolves name to 137.107.3.3 - [ ] No - Is VM2 also resolve by private zone? No, It is resolved by VM4. Why? VM2 in VNET2. VNET2 has DNS server that points to VM4, which is in VNET3. So VM2 uses dns zone in VM4 to resolve the name. - [ ] Yes - Is VM3 resolved by dns zone in VM4? Yes. VM3 in VNET3. VNET3 has DNS server that points to VM4. So it will resolve name to IP address 131.107.2.4

This is one of the several questions asking which one has higher priority - the (custom) DNS bound to a VNET or the private DNS zone linked to the same VNET. According to my test (and also the answer from chatGPT), the private DNS zone has priority. It is the only one which is used if the request is going to a domain hosted by the private DNS zone. If the request is going to a domain which is not in the provate DNS zone, then the default or custom DNS for the VNET is used. Based on this, the answers are Y-Y-Y Why - because both VM1 and VM2 are linked to the private DNS zone, where we have the record for server1.contoso.com -> 131.107.3.3 Also, asuming that the missing explanation of the second table says "VM4 is DNS server and it has the following records", and VM3 points to this DNS server, it will see and resolve the server2.contoso.com -> 131.107.2.4. Note that VNET3 (where VM3 is) is not linked to the private DNS zone.

Im assuming we are missing a line above the table saying "VM4 is a DNS server that contains the following records". If that is the case the answer is YNY Server 1 , A , 131.107.2.3 Server 2 , A, 131.107.2.3

i think this question has been edited. vnet1 uses azure dns. vnet2-3 use 192.168.0.5 vm4 for dns (which we can assume is what the unlabeled 2nd table contains). all vnets are peered so all could use 192.168.0.5 vm4 dns if they wanted. . vm1 is in vnet1, so vm1 uses azure dns. vm2-4 are in vnet3, so vm2-4 use 192.168.0.5 vm4 dns. . yes, vm1 resolves 'server1' to the 3.3 address via azure dns. no, vm2 resolves 'server1' to the 2.3 address via 192.168.0.5 vm4 dns. (not 3.3 via azure dns) yes, vm3 resolves 'server2' to the 2.4 address via 192.168.0.5 vm4 dns.

YNY is the answer. 1. Resolved using Azure Private DNS. 2. Resolved using custom DNS server. 3. Resolved using custom DNS server.

Hello guys, the answer should be YNN. Explanation: When you set custom DNS servers you are specifying the list of DNS servers to be given to VMs via DHCP, which means they will not be querying the Azure private DNS. https://learn.microsoft.com/en-us/answers/questions/1150496/private-dns-vs-custom-dns-for-one-vnet

After: "VNET1, VNET2, and VNET3 are peered." Missing Line: "VM4 has a DNS server that is authoritative for a zone named Contoso.com and contains the records shown in the following table."

They are all peered so i guess YYY?

who can find the official link on which DNS takes precedence: vnet linked DNS or vnet DNS? anyhow this is incomplete question but im gonna assume 192.168.0.5 is the DNS for the 131.107.2.0 records. so answer is Y = VM1 > VNET1 > Azure priv DNS > server1 is 131.107.3.3 Y = VM2 > VNET2 > Azure priv DNS and Custom DNS > I'm gonna say Azure priv will resolve this because of contoso.com,192.168.0.5 does not have contoso.com zone > server1 is 131.107.3.3 N = VM3 > VNET3 > Custom DNS > server2 is 131.107.3.4 for the same reason as above.