I'm new to Azure (strike 1) and totally suck at networking (strike 2).
Nevertheless, I've got two VMs up and running in the same virtual network; one will act as a web server and the other will act as a SQL database server.
While I can see that their internal IP addresses are both in the same network I'm unable to verify that the machines can communicate with each other and am sort of confused regarding the appropriate place to address this.
Microsoft's own documentation says
All virtual machines that you create in Windows Azure can
automatically communicate using a private network channel with other
virtual machines in the same cloud service or virtual network.
However, you need to add an endpoint to a machine for other resources
on the Internet or other virtual networks to communicate with it. You
can associate specific ports and a protocol to endpoints. Resources
can connect to an endpoint by using a protocol of TCP or UDP. The TCP
protocol includes HTTP and HTTPS communication.
So why can't the machines at least ping each other via internal IPs? Is it Windows Firewall getting in the way? I'm starting to wonder if I've chose the wrong approach for a simple web server/database server setup. Please forgive my ignorance. Any help would be greatly appreciated.
If both the machines are in the same Virtual Network, then just turn off Windows Firewall and they will be able to ping each other. Other way is to just allow all incoming ICMP traffic in Windows Firewall with Advanced Settings.
However there is a trick. Both the machines will see each other by IP Addresses, but there will be no name resolution in so defined Virtual Network. Meaning that you won't be able to ping by name, but only by direct IP address. So, if want your Website (on VM1) to connect to SQL Server (on VM2), you have to address it by full IP Address, not machine name.
The only way to make name resolution within a Virtual Network is to use a dedicated DNS server, which you maintain and configure on-premises.
This article describes in details name resolution scenarios in Windows Azure. Your particular case is this:
Name resolution between virtual machines and role instances located in
the same virtual network, but different cloud services
You could potentially achieve name resolution, if you put your VMs is same cloud service. Thus you will not even require dedicated virtual network.
If your VMs are inside a Virtual Network in Azure, then you have to make sure two things.
Required Port is enabled.
Firewall is disabled on the server.
I was trying to connect to one VM where SQL Server DB was installed, from another VM. I Had to enable 1433 port in the VM where SQL was installed. For this you need to add an MSSQL endpoint to the VM on the azure management portal. After that i disabled windows firewall. Then i was able to connect to the VM from another.
Related
I have an Azure Windows Virtual Machine where I have enabled the Inbound Rule Port 8080 under Network Security Group. However, when I try to check the connectivity from my Windows Machine to Azure VM it fails. I used the below command.
>telnet <public_ip_address_of_the_vm> 8080
Connecting To XX.XXX.XXX.XXX...Could not open connection to the host, on port 8080: Connect failed
Note: The VM is enabled with Public IP Address. How to further troubleshoot this issue?
The first thing to do is ensure the VM is running. Then, look at is the Effective Security Rules for the NIC in question.
If the VM has multiple NICs you need to look at the effective rules for each nic (they can be different).
To run a quick test to determine if traffic is allowed to or from a VM, use the IP flow verify capability of Azure Network Watcher. IP flow verify tells you if traffic is allowed or denied. If denied, IP flow verify tells you which security rule is denying the traffic.
If there are no security rules causing a VM's network connectivity to fail, the problem may be due to:
Firewall software running within the VM's operating system
Routes configured for virtual appliances or on-premises traffic. Internet traffic can be redirected to your on-premises network via forced-tunneling. If you force tunnel internet traffic to a virtual appliance, or on-premises, you may not be able to connect to the VM from the internet. To learn how to diagnose route problems that may impede the flow of traffic out of the VM, see Diagnose a virtual machine network traffic routing problem.
Full Troubleshooting Docs with step-by-step instructions.
I'm newbie to OpenStack! I've installed Openstack in Ubuntu Server 18.04 LTS on Microsoft Azure virtual machine (for my learning purpose because I don't have the required resources like 16GB RAM and 4 CPUs). I'm able to access the Openstack Dashboard with the help of public ip address of that VM using the browser in my machine. I've assigned floating ip address to the instance (here it is 172.24.4.8).
My instance specs are
This is my network topology and my azure virtual machine's network configurations
azure vm's private ip = 192.168.0.4
azure vm's public ip = 20.193.227.12
I can access the OpenStack Dashboard using azure vm's public ip address, But I'm unable to access the instance via SSH from my local machine and from that azure virtual machine too. Help me how to access them!
From your network topology screenshot, I guess that you used Devstack to create the cloud. Can you confirm that?
The external network named public is not connected to the world outside the cloud in any way. This is so because by default, Devstack creates an isolated external network for testing purposes. You should be able to access the instance from the Azure VM, however. The information given is not sufficient to explain why you can't.
See the Devstack networking page. It states that the
br-ex interface (...) is not connected to any physical interfaces
This is the technical reason for not being able to access instances.
The Shared Guest Interface section of the above page documents how to connect a Devstack cloud to a real external network.
EDIT:
The Shared Guest Interface instructions ask you to set this:
PUBLIC_INTERFACE= NIC connected to external network. *eth0* in your case.
HOST_IP= *192.168.0.4* for you
FLOATING_RANGE= Your netmask is 255.255.255.128, which translates to a network prefix of 25,
I think. If I am right, the value is *192.168.0.0/25*.
PUBLIC_NETWORK_GATEWAY= The IP address of the router on the *192.168.0.0/25* network.
Q_FLOATING_ALLOCATION_POOL= The range of addresses from FLOATING_RANGE
that you want to use as floating IPs for
your OpenStack instances.
FLAT_INTERFACE might be an old setting for the defunct Nova-Network service. I don't see it mentioned at all in the Ussuri version of Devstack.
We are planning to rent have two VMs (one for Web Server and another for Database server) on Azure. I would like to know what would be the best way to communicate Database server from web server.
Direct communication using DNS.
Keep both the VMs in Cloud service and use host name to communicate.
Form a virtual network and use the persistent virtual machine IP address to connect to.
Thanks In Advance
you don't want to use the Clud Service host name to communicate between the VMs.
If you want to use DNS, you have to provide DNS - you don't need that too.
For that particular scenario, I would recommend something even simpler:
Put the VMs in the same Cloud service
Do not go for any Virtual Network or DNS Solutions
Use VM Name to connect between the machines.
when the VMs are deployed in the same Cloud Service and not in Virtual Network, Windows Azure provides automatic name discovery. The simplest approach is usually the best.
For more information on name resolution scenarios in Windows Azure, read this paper.
Is it possible to connect azure websites (type reserved mode) to a VM in an existing virtual network? I want to configure the connectionstring of the websites to the internal ip of the SQL Server VM and not over it's public ip due to security reasons.
I know that it works with a web/workerrole to connect directly to the internal ip, but it's no option to create all websites within a webrole....
No we don't support Virtual Network (yet) but you can consider using Service Bus Relay for some scenarios, look at http://www.bradygaster.com/windowsazurewebsites-onprem-servicebus
I am trying to connect my Windows Azure Virtual machines to my On Premise network. I have established a site to site VPN tunnel, and have created the appropriate subnets and placed a virtual machine in one of the subnets that isn't the gateway subnet.
My on premise test network is 192.168.9.x/24 my Azure Network is 10.4.x.x/16 with a subnet for DMZ - 10.4.2.x/24 and ServerNetwork at 10.4.3.x/24.
I have confirmed that the tunnel is up and running both on the Windows Azure side, as well as on my Cisco ASA 5505.
I want my servers to be able to communicate across the tunnel, however currently they cannot see each other. I am missing something, I tried static routes between the two servers, and have not had any success. Has anyone gotten this to work? If so what did you do on the networking side of the config to make it work?
Thanks,
Steve
Windows Azure Virtual Network enables you to create secure site-to-site connectivity, as well as protected private virtual networks in the cloud.
You can specify the address space that will be used for both your virtual network and the virtual network gateway.
Additionally, new name resolution features allow you to connect directly to role instances and virtual machines by hostname.
These features allow you to use Windows Azure as you would a branch office, or as a protected private virtual network in the cloud.
You can read more about it here:
http://msdn.microsoft.com/en-us/library/windowsazure/jj156007.aspx
Here is a lab exercise to walk you through the process:
http://www.windowsazure.com/en-us/manage/services/networking/create-a-virtual-network/