Azure : Is it possible to do a cross subscription network peering?

Introduction

Today I received a question if it was possible to do a cross subscription peering… with one big catch; that it was between the subscription of a service provider and their customer(s). So let’s see what is possible?

 

Public Preview Announcement

When we take a look at the announcement, we see the following statement ;

Note that you can peer virtual networks that exist in two different subscriptions as long as a privileged user of both subscriptions authorizes the peering and the subscriptions are associated with the same Active Directory tenant.

Now the from this we can already see that it is possible to doe cross subscription peering. As a requirement, we need a user that is authorized on both subscriptions AND that the subscriptions are associated with the same AAD tenant.

The latter caused a bit of confusion on the requestor part, where the statement was made if a B2B invite would solve this issue. The answer to this is “no”. The B2B invite lies on the authorized user part, and is not related to the tenant of the subscription!

 

Let’s try it out?!?

Continue reading “Azure : Is it possible to do a cross subscription network peering?”

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Azure Star / Any Load Balancer or … like we would like to call it “HA Ports”

Introduction

A few weeks ago the “HA Ports” (finally) saw the light (in public preview)! I’m truly excited about this one, as it had become a “unicorn” for me over the last years.

Why am I so excited about this one? This unlocks of advanced networking patterns, starting with a truly HA setup for the Network Virtual Appliances (NVAs). In the past, we needed to rely on “workarounds” that would switch the UDR to point to the surviving node. That was great for the time, but let’s be honest… It shouldn’t have been like that.

Another use case is the scenario where an application needs to connect to a certain dynamic port ranges (like with SQL). I’ve seen several deployments annoyed by this requirement, which then forced people to create a lot of rules. This can now be avoided by allowing the entire port range, and just hardening it with a “Network Security Group” or Firewall rule base.

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Azure Networking : Blueprint patterns for enterprises

Introduction

When moving to the cloud, one cannot imagine this without some kind of network integration. Taking a look at “Infrastructure-as-a-Service”, there are several common patterns that are utilized by enterprises. Today we’ll discuss these patterns…

 

Typical Network Maturity Models

Embarking on a cloud journey? You’ll typically go through the following patterns depending on your “maturity level” in working with the cloud ;

  1. “Island” : The first approach is typically “the island”. The VMs reside in a VNET that is not connected/integrated with any other networks, except for (maybe) the internet.
  2. “Forced Tunneling” : The first step towards integration is “forced tunneling”. Here you want to access “On Premises” resources, though the mass of the resources on Azure do not justify the investment into a “Network Virtual Appliance” (AKA Firewall). Here you set up a “UDR” (User Defined Route, AKA Static Route), where you force all traffic to go back to the “On Premises” network.
  3. “Single VNET with DMZ” : One step beyond “forced tunneling”, is moving towards the typical DMZ-alike pattern, where you setup a HA-pair of “Network Virtual Appliances” and segregate network zones.
  4. “Hub & Spoke”-model : Growing even further, you’ll have multiple subscriptions. Setting up “NVAs” on all of those can be quite expensive. In terms of governance, this also a nice model, where you can consolidate all network integration into a segregated subscription/vnet.

The advantage of these patterns is that you can evolve into another pattern without breaking anything in terms of design.

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Azure : What the BGP is going on there?

Introduction

Something I had on my to-do for a while now was to post a proof-of-concept to you guys/gals about what BGP on Azure can entail… Now some of you might go; “BGP? What the hell is that?!?”. Check out the following “CBT Micro Nugget” as it is a nice high level description of what BGP is.

 

So why should you care? BGP can offer you a way to deal with advanced routing paths. This in turn can deliver resiliency to your business.

 

Proof-of-Concept Design

For today, we’ll be building the following setup ; kvaes-azure-networking-bgp-resiliency

This will consist of the following components ;

  • Four virtual networks ; VNET001, VNET002, VNET003 & VNET004
  • Each VNET will have its own VPN Gateway. We’ll enable BGP on the VPN Gateway and give it its own (unique for, and private to, our deployment) ASN & peering address. The VPN Gateway will be set to “RouteBased”-routing and we’ll use a “Standard” SKU.
  • Each VPN Gateway will have two connections towards the “previous” and “next” gateway. The keys per connection pair will be set to the same key and we’ll also enable BGP on the connection.
  • We’ll deploy two systems into this PoC setup
    • System001 will reside in VNET001
    • System004 will reside in VNET004

 

To test our setup, we’ll execute the following scenario ;

  • Connect from system001 to system004 whilst our ring is complete =>the green path will be followed
  • Connect from system001 to system004 whilst having deleted the connections between VPNGW001 & VPNGW004 => the yellow path will be followed

Continue reading “Azure : What the BGP is going on there?”

Azure : A poor man’s SSL termination (by leveraging Cloudflare)

Introduction

A few weeks back I posted some posts about the Azure Application Gateway. Here I must say I ran into some issues in combination with Rancher. So I was forced to look for alternatives…

One of my requirements was to have a “zero-touch deployment”-capability. Meaning that I did not want to deploy a system where I had to manually change things to get it working.

 

High Level Blueprint

So how would a “poor man’s ssl termination on Azure” look? Basically I’m using Cloudflare as my DNS provider which then provides capabilities like CDN, various SSL options (like SSL Termination = Flexible SSL), WAF, etc. We can start with the free plan, where we can do a redirect to https and do SSL termination.

kvaes-azure-cloudflare-poorman-ssl-termination

In addition, we’ll deploy an NSG (network security = basic azure firewall rule) that is configured to only allow the IP ranges from Cloudflare. This way we speak https on the outside world, and we have to accept that the traffic between Cloudflare and our hosts is unencrypted…

 

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