We have a Azure internal load balancer forwarding request to backend VM'S.
Is there a way to find out how many requests are server by each VM ? In other words how many requests are forwarded to each VM from the load balancer.
You could adopt Standard Load Balancer. You will see some differences between Standard Load Balancer and Basic Load Balancer in that linking document. For internal standard LB, you can check the SYN (synchronize) packets metric which collecting flows and their handshakes are always between the source and the VM instance.
For other scenarios, you could collect the network trace by networking capturing tool like Wireshark.
Related
I have created a internal load balancer in azure and backend pool configured two vm's health probe and rule also configured, If I browse the Load balance ip it work fine but while i'm checking the ping request from the VM to Load balancer it shows time out error. Is it possible to make a successful ping request.
Regular icmp traffic is not allowed on Azure load balancers, you should either try a port ping (psping), telnet, nmap, nc, or other utilities to check E2E connectivity.
Some extra details here:
https://social.msdn.microsoft.com/forums/azure/en-US/e9e53e84-a978-46f5-a657-f31da7e4bbe1/icmp-outbound-ping-on-azure-vm
Not only ICMP, any traffic from backend VM to frontend IP of internal load balancer will not work. This is one of the limitation of azure internal load balancer.
Bhuvanesh Kumar Kumaresan, Cloud Solution Architect
Please forgive my ignorance.
Question:
How can I control network traffic to a publicIP resource and send it to multiple different resources based on destination port?
Background:
I have setup some VMs that are configured with only private IPs in different subnets. All belong to the same Virtual Network. All these VMs have different services and I do not want HA as I do not need it and it costs money.
I just want all the services on these VMs to communicate out using the same single publicIP and I want to split incoming traffic to that same publicIP between my resources based on destination port.
Seems like a straight forward requirement right?
At first I though "this must be a task for the Load Balancer service" as it's operating at L4 and tried to set it up but I was not able to split inbound traffic on different ports to more than a single VM or a single availability set. I do not understand why you can only use Load Balancers NAT rules with a single VM or Availability Set.
I can probably delete/re-create all VMs (thank you Microsoft..) into a single availability set that only has 1 fault and 1 error domain but does this make any sense?
It just seems to me like a dirty workaround using availability sets in a way they are not meant to in order to solve a very basic thing.
Thanks!
Basically, you could create a public-facing Azure Load balancer then target the VMs or Availability Sets to the backend pools of this load balancer. What you need to do is to configure the load balancing rules and some health probes or inbound NAT rules for the backend services with ports forwarding.
Refer to the SO answer.
You would use NAT rule when you have 1 backend server or you know
which backend server to get to and load balancing rules when you want
to load-balance to multiple backend servers.
NAT rule must be explicitly attached to a VM (or network interface) to
complete the path to the target; whereas Load Balancing rule need not
be. In the latter case, a VM is selected (from the back-end address
pool or VMs) to complete the path to the target.
Additionally, Azure Load balancer supports two SKUs: basic and standard. Different SKUs support different backend pool endpoints. Read more details about Load Balancer SKU comparison.
In my application, I needed IPv6 support for WAF. Since IPv6 yet not supported by the WAF can I use a load balancer connected to the WAF as the following diagram (because of IPv6 supports Load Balancer)? Is this a good design?
You can not use the Azure load balancer to connect to an application gateway since Azure load balancer only works with VM, VMS, or availability sets as its backend. Have a look at backend pool endpoints here.
More info: Overview of IPv6 for Azure Load Balancer
I created an internal load balancer in Azure with 2 vms connected to it, what is the best way to test it?
Thanks
Depending on your end goal, you should be able to set up an IIS/Apache/nginx website, depending on your VM operating system. After that, create a simple load balancing rule for port tcp 80 and see if the configured website responds.
Pretty sure you could also create a load balancing rule for RDP (tcp 3389) or SSH (tcp 22) and test to connect against your load balancer IP address.
If you are unsure whether your LB or back-end services are functional, refer to this: https://learn.microsoft.com/en-us/azure/load-balancer/load-balancer-troubleshoot
I have a very simple Azure VM setup. One VM is behind an Internal Load Balancer, and it's private IP address is 10.0.1.10.
A Web Service is running in that VM. I can access website by using http://localhost, but as per my software requirement, I have to use Load Balancer private IP address instead of localhost. But I can not browse with Internal Load Balancer IP address (http://10.0.1.10 does not work from that VM).
Is that by design that I can't access Internal Load Balancer by it's private IP address? Or I need to do something special to make it work?
There's a difference between public and internal Azure Load Balancer configurations.
When Azure Load Balancer is used in a public load balancer configuration, SNAT is used for outbound requests. This means a VM behind a public can reach the public IP address of the load balancer and the flow will be load balanced accordingly. This will consume an ephemeral port for each connection to the VIP.
Internal load balancer configurations do not offer SNAT today. In turn, an internal load balancer configuration does not allow a pool member to access the IP address of the internal load balancer.
We are looking at addressing this in a future release by allowing an option to enable SNAT for internal load balancers as well. Mandatory SNAT can actually impose constraints for those who don't need to access the IP address of the load balancer, and therefore this needs to be an option rather than the default.
According to your description, do you means that the VM in the load balancer and the web service running on the VM, you want to use the VM to browse the internal load balancer IP, but it doesn’t work.
I had test in my lab, and the same error occurred. By the way, the load balancer can’t work in this way.
Here is my network capture result:
Maybe we should to create a new VM outside of the load balancer, then you can browse the load balancer IP. Because once a network interface is added to a load balancer's back-end IP address pool, the load balancer is able to send load-balanced network traffic based on the load-balanced rules that are created.
If you still have questions, welcome to post back here. Thanks.
Best Regards,