I had a need to add additional public IP addresses to an Azure VM and found a working solution here:
Azure VM: More than one Public IP
Essentially this creates a reserved IP in Azure and then adds the reserved IP to a cloud service. Once it's bound to a cloud service it can be mapped to a VM endpoint.
This all works great but there is one bit I don't understand - The IP address of the reserved IP and the resultant VM endpoint don't match. I have to set up DNS to point to the IP address of the endpoint to make this work. Is there something I am not doing right, or is this just the way reserved VMs work?
It looks like this unanswered question is the same issue:
azure reserved IP for VM is diffrent than the given
Thanks!
The "Azure Cloud Service" is a container that provides internet connectivity to "Azure VMs". Thus, you assign the Internet facing Public IP to the Cloud Service. This article is relatively good at explaining the relationship: Azure Cloud Services
From above link:
Here’s a definition of an Azure IaaS cloud service that will make it easy for you to understand what it is in the context of Azure Infrastructure Services:
A cloud service is a network container where you can place virtual machines.
All virtual machines in that container can communicate with each other directly through Azure (and therefore don’t have to go out to the Internet to communicate with each other).
This container is also assigned a DNS name that is reachable from the Internet.
A rudimentary DNS server is created and can provide name resolution for all virtual machines within the same cloud service container (note that name resolution provided by the DNS server is only available to the virtual machines that are located within the cloud service).
One or more Virtual IP Addresses (VIPs) are assigned to the container and these IP addresses can be used to allow inbound connections from the Internet to the virtual machines.
Certain services (like FTP) may require your vm have a public IP: Azure VM Public IP
(IaaS v1) An Azure cloud service comes with a permanent DNS name - something.cloudapp.net - and has a single VIP allocated whenever there are VMs deployed in it OR whenever a reserved IP address is associated with it. Traffic is either load balanced or NATted (port forwarded) to the VM from the Azure Load Balancer sitting on the VIP. You can also associate a public instance-level IP address (PIP) with a VM, which gives it an additional IP address. The VIP always has a DNS name (something.cloudapp.net) while the PIP has one only if you specifically add it, I did a post which goes into these differences.
(IaaS v2) VMs are not deployed into cloud services and only have a public IP address if one is specifically added - either by configuring a PIP on the NIC of the VM (and optionally giving it a cloudapp.azure.com DNS name) or by configuring a load balancer and either load balancing or NATting traffic to it. This load balancer is configured with a public IP address and can optionally have a cloudapp.azure.com DNS name associated with it. (Ignoring internal load balancers in this discussion.)
Related
I have created a Virtual Machine Scaleset in Azure
This scaleset is made up of 5 VMs
There is a public ip
When I do a ping on my public ip I get no response, nor do I get a response with the full name, e.g.
myapp.uksouth.cloudapp.azure.com
Is there something I have missed?
I am wondering if I have to add my machine's IP somewhere?
I am trying to remote into the machines within the scaleset eventually!
This scaleset will be used for azure service fabric
Paul
If you deploy your scale set with "public IP per VM", then each VM gets its own public IP: https://learn.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-networking#public-ipv4-per-virtual-machine. However, this is not the default in the portal. In the portal, the default is to create a load balancer in front of the scale set with a single public IP on the LB (today, at least; no guarantee it will stay this way). It also comes with NAT rules configured to allow RDP/SSH on ports 50000 and above. They won't necessarily be contiguous, though (at least in the default configuration), so you will need to examine the NAT rules on the load balancer to see which ports are relevant. Once you do, you should be able to do ssh -p <port-from-nat-rule> <public-ip> to ssh in (or similar in your RDP client for Windows).
When I do a ping on my public ip I get no response
Azure does not support ping.
For test, you can use RDP/SSH public IP address with different ports to test the connection.
Are you create VMSS with Azure marketplace? If yes, the Azure LB will configured.
If the load balancer created by your self, please check LB probes, backend pools(all vms should in that backend pools), load balancer rules and NAT rules.
Also you can configure log analytics for Azure load balancer to monitor it.
I have an azure network set up with the default Azure DNS.
All the VMs are ubuntu.
When I try to access another VM on the network via the public DNS name it resolves to the public IP.
How do I make it resolve to the internal IP when I request it from the virtual network (and obviously still resolve to the public IP when requested externally).
I'm interested in cli answers as well as configurations through the portal.
Azure DNS for IaaS and PaaS solutions
Please see this article for more information on Azure's own DNS service associated with virtual networks. In short
When role instances and VMs hosted in Azure need to resolve domain
names to internal IP addresses, they can use one of two methods:
Azure-provided name resolution
Name resolution that uses your own DNS server (which might forward queries to the Azure-provided DNS servers)
The type of name resolution you use depends on how your VMs and role
instances need to communicate with each other.
Azure DNS Private Zones (in preview)
There's also a relatively new service called, Azure DNS Private Zones that allow you to set up a private DNS service to be used with, for example virtual networks.
This service allows you to set up a private domain and private IPs for your machines. See this page for more information and some common usage scenarios.
Also, see this this feature suggestion:
Enable split DNS for providing both public and internal name resolution to VMs in the VNET
I have 2 different virtual networks set up in azure. The first of these virtual networks contains virtual machines in which I am able to set the internal virtual network IP as 10.101.1.4, 10.101.1.5, 10.101.1.6 on the virtual machines by using the preview portal to set the IP address
In my other virtual network I have a VPN connection and from the virtual network I add a Cloud service which we have informed the other side of the VPN will be available on 10.103.1.4 but for some reason this has now changed to 10.103.1.5
Is there any means of ensuring that the cloud service will always be deployed to the 10.103.1.4 IP address within the virtual network?
an compute instance or an azureVM get an IP-Adresse via DHCP and the lease time is 100+ years. to set a specific IP-Adresse to an azureVM/compute instance you can define a "static ip reservation" in your own VNET to this instance. e.g. via powershell, the new portal or via your cloud service configuration schema.
check out this link: https://azure.microsoft.com/en-us/blog/reserved-ip-addresses/
regards
patrick
I have an Azure Cloud Service, mywebapp.cloudapp.net, that consists of two Azure VMs - mywebappvm1 and mywebappvm2. Both VMs are in the same Availability Set and have the same DNS name.
I also have a Regional Reserved IP address assigned to the Cloud Service so that I can give our clients a guaranteed IP address that our app uses.
Part of the app uses a private background process, currently only running on one of the VMs. I want to be able to make a connection to that process over TCP running on mywebappvm1 from mywebappvm2. I could use the public IP and an endpoint on mywebappvm1 but I don't want the background service to be publicly accessible.
I'm currently using the private IP address, but is that safe? Will the private IP of each VM change if it's rebooted? I can't see an easy way of fixing the private IP of each VM - that seems like something you can do with a VNET but I can't find any information on how to do it with a cloud service and an availability group as well.
Is there perhaps another way to run a web app on multiple load-balanced VMs within an availability set that would make this easier?
What you do is absolutely safe and actually a recommended best practice. You should not go out to public IP address in order to communicate between the Virtual Machines.
It is also a recommended best practice to organize your Virtual Machines into Virtual Network and sub-nets.
This excellent blog post describes how can you even use static IP addresses for the VMs, so you are always 100% sure that mywebappvm1 always get XXX.XXX.XXX.XXX IP Address andyour mywebappvm2 always get YYY.YYY.YYY.YYY IP Address.
Please note that if you do not use Static IP Address assigned to the VM, it is guaranteed that the IP Address of the VM may change.
The IP for a webRole VM instance will not change for the lifetime of the deployment regardless of reboot, update or swapping. The IP will be released only if you delete the deployment, detailed here
I want to have three public ip addresses for my VM in azure. I got one when I created the VM and now I want to assign two reserved ip addresses to my VM. I was able to create the reserved ip address but not sure how to assign them to existing VM or assign multiple to a new VM. Any suggestions on how to do this?
In Azure, a Load Balancer is required in order to direct traffic from multiple VIP addresses to a single (or multiple) VMs.
If, for example, you want a single VM to host multiple websites, all of which need to be accessible externally via port 443, you'd need three VIP addresses assigned to the Load Balancer, with a NAT on each at least two of the VIPs; i.e.
Site a: Incoming 443-443 to VM
Site b: Incoming 443-444 to VM
Site c: Incoming 443-445 to VM
All the traffic from the Load Balancer could then be routed to one VM, where you'd direct traffic on each incoming port to the required website based. This MS article explains it really well: https://azure.microsoft.com/en-gb/documentation/articles/load-balancer-multivip/
Reserved IP addresses are a way of ensuring that your VIP is no longer dynamic, which they are by default. The following article explains it well, including how to take an existing Cloud Service's currently-running dynamic VIP and making it static (Reserved): https://azure.microsoft.com/en-gb/documentation/articles/virtual-networks-reserved-public-ip/
An Azure VM can have two public IP addresses - one is the VIP of the cloud service containing the VM (as long as there are endpoints configured for the VM) and the other is the PIP (or public instance IP address) associated with the VM. A reserved IP address is an orthogonal concept to VIPs and PIPs and its use is documented here. I did a post on VIPs, DIPs and PIPs that you may find helpful.