Azure VNets and 172.16.0.0/12

5th of February, 2020 / / No Comments

I’ve recently been digging into the weeds of doing an Azure VNet Hub and Spoke design for a customer and it’s brought about revisiting a topic from a while back.

For some quick context- for any given VNet in Azure there is a System RouteTable that holds basic routing information for that VNets network traffic flows within that VNet as well as inbound and outbound of the VNet. The following table outlines what the default System RouteTable routes consist of (table information source):

 

So, whats the problem with that?

… [Keep reading] “Azure VNets and 172.16.0.0/12”

Hub-Spoke communication using vNet Peering and User Defined Routes

10th of August, 2018 / / 1 Comment

Introduction

Recently, I was working on a solution for a customer where they wanted to implement a Hub-Spoke virtual network topology that enabled the HUB to communicate with its Spoke networks via vNet Peering. They also required the SPOKE networks to be able to communicate with each other but peering between them was NOT allowed.
Drawing1
As we know, vNet peering is Non-Transitive – which means, even though SPOKE 1 is peered with the HUB network and the HUB is peered with SPOKE 2, this does not enable automatic communication between SPOKE 1 and SPOKE 2 unless they are exclusively peered which in our requirement we were not allowed to do.… [Keep reading] “Hub-Spoke communication using vNet Peering and User Defined Routes”

Secure Azure Virtual Network Defense In Depth using Network Security Groups, User Defined Routes and Barracuda NG Firewall

25th of August, 2015 / / 3 Comments

Security Challenge on Azure

There are few common security related questions when we start planning migration to Azure:

  • How can we restrict the ingress and egress traffic on Azure ?
  • How can we route the traffic on Azure ?
  • Can we have Firewall kit, Intrusion Prevention System (IPS), Network Access Control, Application Control and Anti – Malware on Azure DMZ ?

This blog post intention is to answer above questions using following Azure features combined with Security Virtual Appliance available on Azure Marketplace:

  • Azure Virtual Network (VNET)
  • Azure Network Security Groups (NSGs)
  • Azure Network Security Rule
  • Azure Forced Tunelling
  • Azure Route Table
  • Azure IP Forwarding
  • Barracuda NG Firewall available on Azure Marketplace

One of the most common methods of attack is The Script Kiddie / Skiddie / Script Bunny / Script Kitty.… [Keep reading] “Secure Azure Virtual Network Defense In Depth using Network Security Groups, User Defined Routes and Barracuda NG Firewall”

Azure VNET gateway: basic, standard and high performance

23rd of July, 2015 / / 6 Comments

Originally posted @ Lucian.Blog. Follow Lucian on twitter @Lucianfrango.

I’ve been working a lot with Azure virtual network (VNET) virtual private network (VPN) gateways of late. The project I’m working on at the moment requires two sites to connect to a multi-site dynamic routing VPN gateway in Azure. This is for redundancy when connecting to the Azure cloud as there is a dedicated link between the two branch sites.

Setting up a multi-site VPN is a relatively streamlined process and Matt Davies has written a great article on how to run through that process via the Azure portal on the Kloud blog.

Read More

Mule ESB DEV/TEST environments in Microsoft Azure

16th of February, 2015 / / No Comments

Agility in delivery of IT services is what cloud computing is all about. Week in, week out, projects on-board and wind-up, developers come and go. This places enormous stress on IT teams with limited resourcing and infrastructure capacity to provision developer and test environments. Leveraging public cloud for integration DEV/TEST environments is not without its challenges though. How do we develop our interfaces in the cloud yet retain connectivity to our on-premises line-of-business systems?

In this post I will demonstrate how we can use Microsoft Azure to run Mule ESB DEV/TEST environments using point-to-site VPNs for connectivity between on-premises DEV resources and our servers in the cloud.… [Keep reading] “Mule ESB DEV/TEST environments in Microsoft Azure”

Secure Azure Virtual Network and create DMZ on Azure VNET using Network Security Groups (NSG)

7th of November, 2014 / / 20 Comments

At TechEd Europe 2014, Microsoft announced the General Availability of Network Security Groups (NSGs) which add security feature to Azure’s Virtual Networking capability. Network Security Groups provides Access Control on Azure Virtual Network and the feature that is very compelling from security point of view. NSG is one of the feature Enterprise customers have been waiting for.

What are Network Security Groups and how to use them?

Network Security Groups allow us to control traffic (ingress and egress) on our Azure VNET using rules we define and provide segmentation within VNET by applying Network Security Groups to our subnet as well as Access Control to VMs.… [Keep reading] “Secure Azure Virtual Network and create DMZ on Azure VNET using Network Security Groups (NSG)”

Highly Available SQL 2012 across Azure VNET (Part 1: VNET Peering)

1st of August, 2014 / / 1 Comment

Just over a year Microsoft announced the support of SQL Server AlwaysOn Availability Groups (AAG) on Microsoft Azure IaaS. Last month, Microsoft announced the support of SQL AAG between Azure Regions. This is a great news for great technology like SQL Server 2012 for highly available and disaster recovery scenario. SQL AAG released in SQL 2012 and enhanced in SQL 2014. AAG will detect anomaly which will impact SQL availability. When We will discuss how to do this in two blog posts:

  • Part1: Design SQL 2012 AAG across Azure VNET and How to create Microsoft Azure VNET to VNET peering
  • Part2: SQL, WSFC, Configure Quorum and Voting (SQL) and Configure AAG

Part1 SQL 2012 AAG across Azure VNET SQL 2012 AAG is designed to provide high availability for SQL database and Azure IaaS is great place where this technology can live.… [Keep reading] “Highly Available SQL 2012 across Azure VNET (Part 1: VNET Peering)”

Bad Request: Internal Load Balancer usage not allowed for this deployment

20th of May, 2014 / / 2 Comments

Microsoft released a number of new networking features for the Azure platform this week:

  • Multiple Site-to-Site VPNs
  • VNET-to-VNET Secure Connectivity
  • Reserved IPs
  • Instance level Public IPs
  • Internal Load Balancing

Announcement details can be found on Scott Gu’s blog post

Internal load balancing (ILB) was a much needed networking feature that will enable the design of highly available environments in hybrid infrastructure scenarios. Until now, 3rd party solutions were required to load balance workloads in IaaS virtual machines when accessed by on-premise (internal) clients across the site-to-site VPN.… [Keep reading] “Bad Request: Internal Load Balancer usage not allowed for this deployment”