Whenever i'm adding a VM(Windows/Linux) to the backend pool of a Standard(not basic) Internal load balancer, the VM loses internet access(outbound) to all the internet sites(example: www.google.co.in) except Microsoft sites(bing.com).
Things i have tried:
1. Created Health probe and load balancing rules to verify the load balancing is happening - and yes the load balancing works but no internet access
2. DisableOutboundSNAT on the Rule - load balancing works but no internet access
3. Created NSG to allow all outbound traffic (which is enabled by default) - no luck
Finally this issue is resolved.
This is by design as mentioned on here:
So for a conclusion, if we want to access internet from the VM behind a Standard ILB, we need to associate a Public IP to the VM. ( I tested it and it worked).
Also, this seems a very good design as VM is completely private(no outbound implicitly) when it is behind a Standard Load Balancer.
Thanks to Micah for resolving this on this post.
Related
Disclaimers: I come from AWS background but relatively very new to GCP. I know there are a number of existing similar questions (e.g, here and here etc) but I still cannot get it work since the exact/detailed instructions are still missing. So please bear with me to ask this again.
My simple design:
Public HTTP/S Traffic (Ingress) >> GCP Load Balancer >> GCP Servers
GCP Load Balancer holds the SSL Cert. And then it uses Port 80 for downstream connections to the Servers. Therefore, LB to the Servers are just HTTP.
My question:
How do I prevent the incoming HTTP/S Public Traffic from reaching to the GCP Servers directly? Instead, only allow the Load Balancer (as well as it's Healthcheck Traffic)?
What I tried so far:
I went into Firewall Rules and removed the previously allowing rule of Ports 80/443 (Ingress Traffic) from 0.0.0.0/0. And then, added (allowed) the External IP address of Load Balancer.
At this point, I simply expected the Public Traffic should be rejected but the Load Balancer's. But in reality, both seemed to be rejected. Nothing reached the Servers anymore. The Load Balancer's External IP wasn't seemed to be recognised.
Later I also noticed the "Healthchecks" were also not recognised anymore. Therefore Healthchecks couldn't reach to Servers and then failed. Hence the Instances were dropped by Load Balancer.
Please also note that: I cannot pursue the approach of simply removing the External IPs on the Servers. (Although many people say this would work.) But we still want to maintain the direct SSH accesses to the Servers (by not using a Bastion Instance). Therefore I still need the External IPs, on each and every Web Servers.
Any clear (and kind) instructions will be very much appreciated. Thank you all.
You're able to setup HTTPS connectivity between your load balancer and your back-end servers while using HTTP(S) load balancer. To achieve this goal you should install HTTPS certificates on your back-end servers and configure web-servers to use them. If you decided to completely switch to HTTPS and disable HTTP on your back-end servers you should switch your health check from HTTP to HTTPS also.
To make health check working again after removing default firewall rule that allow connection from 0.0.0.0/0 to ports 80 and 443 you need to whitelist subnets 35.191.0.0/16 and 130.211.0.0/22 which are source IP ranges for health checks. You can find step by step instructions how to do it in the documentation. After that, access to your web servers still be restricted but your load balancer will be able to use health check and serve your customers.
I have a tomcat server with port 8080 which is running on a Google cloud platform VM instance. Also i have enabled SSL for my server. In that i have deployed my web application. When i enter my domain name in browser my application will be running.
But it will be appended with the port 8443. It looks like hostname:8443. By using load balancing in GCP i can able to achieve it. But i am new to GCP so i don't know how to configure and all. Eventhough i have configured but it shows some error like problem with backend service.
Kindly anyone can help me to resolve this.
If I understand correctly you would like to know whether in the DNS record you need to add VM instance External IP or Load Balancer’s External IP address. If my understanding is correct, in order to use Load Balancer, you need to put the load balancer’s External IP in your DNS A record.
Regarding your 1 backend service is unhealthy, I would request you to check ‘Firewall rules’ section of GCP’s Creating Health Checks documentation. You need to create ingress firewall rules applicable to all VMs being load balanced to allow traffic from health check prober IP ranges. You did mentioned which load balancer you are using. You will find GCP load balancers offering from this link. Based on the Load Balancer you are using, you need to create an appropriate heal check firewall rule.
I would recommend posting this type of questions in ServerFault as StackOverflow is for Q&A for professional and enthusiast programmers.
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'm trying to build a simple two-tier wordpress environment on CentOS 7.2 in Azure.
I've defined a virtual network, have connected it to my home-lab via IPsec VPN, and I've defined several subnets in Azure (for Web tier, SQL tier, and utility tier role segregation using Network Security Groups).
I have two web-tier VMs, both members of the same Availability Set, and are both on the web-tier subnet. They have internet access (outbound), I can SSH to them from my home-lab, and the seem fine operationally to me - httpd is listening on 80/tcp, and I can hit the web pages from my home-lab network by visiting each web server directly on its 192.168.x address.
I should mention my web servers DO NOT have public IPs assigned, but I can't see this being an issue.. they're intended to be behind the load balancer.
So, I've created a Load Balancer, and:
assigned a public IP to the LB
added a backend pool (selected my availability set, and chose my two web servers)
added a probe (http probing the two web servers)
added a load balancer rule
Notice I did NOT add an inbound NAT rule. I can't figure out what that's for, or if I need it.
On my web tier, I tcpdump port 80 and see the probes. In httpd logs, I see 200 success messages for the probes. I go to a web browser, hit the external VIP I assigned to the LB, and nothing. It just times out. I cannot connect to the LB VIP.
What am I missing? What are the NAT rules about?
Any help would be appreciated. All I can find online are examples doing this in powershell etc.. and I'm using the Azure web interface.
Thanks!
Edit: Found the issue - Needed the NSG to allow not just the AzureLoadBalancer, but "Internet" to hit port 80/tcp. Should have thought of that sooner..
Found the issue - Needed the NSG to allow not just the AzureLoadBalancer, but "Internet" to hit port 80/tcp. Should have thought of that sooner..
I am evaluating the convenience of moving to azure. Currently, I am trying to figure out how to balance the load and make routing for different websites on the same machine. I saw tutorials where a user created a separate LB on a different VM. I also found many articles about the possibility to balance the load using Azure load balancing.
So I assume both are possible, is that correct?
I would like to know how to connect between machines on azure. Would it be possible to do so using a local ip, machinename, or dns?
I also need to figure out how to forward traffic to different ports based on http header, is that possible without a seperate machine as load balancer? I see the endpoint config in my azure dashboard and found the official documentation, but unfortunately it's not enough for my understanding.
Currently, I am trying to figure out how to balance the load and make
routing for different websites on the same machine.
You can have different web sites on the same machine by configuring virtual hosting on IIS. This is accomplished using host header. VM, Cloud Service or even Websites supports this functionality. VMs and Cloud Services should be pretty straight forward. Example using websites:
Hosting multiple domains under one Azure Website
http://blogs.msdn.com/b/cschotte/archive/2013/05/30/hosting-multiple-domains-under-one-azure.aspx
I also found many articles about the possibility to balance the load
using Azure load balancing.
LB for VMs are as easy as creating a load balance set inside endpoint configuration wizard. Once you create a balance set, for example, enpoint HTTP port 80, you can assign this balance set to any VM on the same cloud service. All requests to port 80 would be automatically balanced across all VMs in the set.
So I assume both are possible, is that correct?
Yes.
I would like to know how to connect between machines on azure. Would
it be possible to do so using a local ip, machinename, or dns?
You just have to create a virtual network and deploy the VMs to it. Websites (through preview portal only), Cloud Services and VMs supports VNet.
Virtual Network Overview
https://msdn.microsoft.com/library/azure/jj156007.aspx/
I also need to figure out how to forward traffic to different ports
based on http header, is that possible without a seperate machine as
load balancer?
Not at this moment. Best you can have with native Azure Services is a 3-tuple (Source IP, Destination IP, Protocol) load balance configuration.
Azure Load Balancer new distribution mode
http://azure.microsoft.com/blog/2014/10/30/azure-load-balancer-new-distribution-mode/
depending on how you're deploying there's a couple of options:
first of all: LB sets in VM's in a cloud service. For this the Cloud service acts as the LB. this can only be achieved when using a standard sku VM.
second of all in Azure WebApps : load balancing is achieved automagically when deploying through standard means, since scaling is foreseen here.
Third of all there's Cloud Services with roles, who also do this "automagically".
Now none of that seem to apply to your needs. you can also start thinking about using traffic manager, something with a little more bite :-)
have you read this article by any chance? http://azure.microsoft.com/en-us/documentation/articles/virtual-machines-load-balance/
I'd like to advise you to add different endpoints to your VM's work with traffic manager and ake sure you IIS has all the headers on the correct ports (cause i'm assuming that's what you're doing already)