Azure VMS cannot connect each other

skak 21 Reputation points
2023-11-22T08:11:07.17+00:00

Hello All,

I have a free Azure account where I am choosing free services and creating Virtual Machines namely VMA and VMB. I have also created an inbound rule for ICMP to allow ping traffic but they cannot ping each other.

I have also seen a strange issue when ever a new VM is created it gets 10.1.1.4/24 ip address for all the VMS.

Your help will be apprectiate

Thansk

Skak

Azure Virtual Machines
Azure Virtual Machines
An Azure service that is used to provision Windows and Linux virtual machines.
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  1. vipullag-MSFT 25,861 Reputation points
    2023-11-22T08:43:48.8566667+00:00

    Hello skak

    Welcome to Microsoft Q&A Platform, thanks for posting your query here.

    For your 1st query on ICMP issue, as long as the VMA and VMB are in same VNET, no NSG is required (Default ICMP access is allowed).

    But you must allow it in the OS of both VMs:

    Ex: For Windows, open CMD as admin and run below 

    netsh advfirewall firewall add rule name="ICMPv4 Allow Ping Requests" protocol=icmpv4:8,any dir=in action=allow

    For the 2nd issue on IP address, your statement is not clear.

    The first VM in the subnet of "10.1.1.0/24" will get 10.1.1.4 only. From there, .5 then .6 and so on...

    What is the subnet range where you are deploying the VM? Can you please elaborate more on this issue?

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  2. Deepanshukatara-6769 7,750 Reputation points
    2023-11-22T08:43:52.65+00:00

    Hi , hope doing well

    To answer this please check below

    1. IP Address Assignment Issue (10.1.1.4/24 for all VMs):

    It seems like your virtual network might be using Azure's default subnet (10.1.1.0/24) for IP address assignment. When you create multiple VMs within the same virtual network and subnet, Azure assigns IP addresses sequentially, which is why they all receive similar IPs.

    To resolve this:

    • Custom Subnets: Consider creating custom subnets within your virtual network to avoid IP conflicts. This allows you to create different address ranges for different groups of VMs.
    • Reserve IP Addresses: Alternatively, you might reserve specific IP addresses within the subnet for each VM to ensure unique addresses.
    • Address Space Planning: Review your address space planning and subnet configuration in Azure to ensure that it accommodates the number of VMs you intend to create without causing IP conflicts.

    Please accept answer if it helps , Thankyou!

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  3. skak 21 Reputation points
    2023-11-22T10:27:34.7866667+00:00

    I think I have found the issue, the free services from Azure lets you create the VM but when ever a new VM is created it will create a new resource group and new VNET BUT DOESN'T ASKS FOR EXISTING RESOURCE GROUP while in the paid VERSION of Azure you can choose existing Resource Group while Creating a VM .