10 posts tagged with "Security"

The impending deadline of Azure IP armageddon is nearly upon us. In September a fairly major shift is taking place in Azure which will see a change to the default behaviour for outbound internet for Azure VMs. The change itself has been fairly well discussed but you can now get ahead of the curve with Azure Private Subnet and start building things as they will be after September.

The shift from traditional network perimeters to zero trust architectures represents one of the biggest changes in cybersecurity thinking over the past two decades. But there's a dangerous misconception floating around that zero trust means ditching network security controls for identity-based systems. This misunderstanding has led many organisations to roll out incomplete solutions that create new vulnerabilities while trying to fix legacy security problems.

I've already written a bit about various firewalls and their performance with FQDN filtering. I've also made the case for a 'less is more' approach to egress security where it makes sense. But the topic of FQDN filtering keeps coming up, so I thought I'd share a few more thoughts on it.

A little while ago I set out to find a way to measure the overhead that FQDN filtering places on HTTPS web traffic. I've shared the results here, but I thought I'd take the opportunity to discuss the methodology in a bit more detail.

I took a look at egress security a little while ago and advocated for the 'less is more' approach for most organisations due to the proliferation of VPCs and vNets and the risk of either having a very large amount of very expensive firewalls providing very little value or, perhaps worse, another pet in the form of centralised internet egress. But I think there may be another way.

A good friend of mine is taking his AZ-700 next week and asked me a few questions about Azure Traffic Manager, Azure Front Door and the WAF capabilities in Azure. Some of the questions in his practice exams were a bit confusing. As he's not only a good friend but also the kind chap who proof reads a lot of these blog posts, I thought I'd try to explain what the options are and when you'd use them. On a side note, if you fancy talking to a top tier network guy and all-round nice fella, I thoroughly recommend you look up Zain Khan.

The Business Case Challenge

I've found that traditional justifications for SD-WAN adoption have often focused on cost savings versus MPLS or enhanced network features. However, these arguments frequently fall short under scrutiny. The fundamental challenges that limited VPN adoption in enterprise networks – including performance consistency, reliability, and operational complexity – remain relevant despite improvements in internet infrastructure.

The Case for Application-Level Controls

Introduction​

I've noticed that an organisation's approach to securing outbound internet traffic often reflects its security maturity more than its technical requirements. System-to-system communication, such as API calls to cloud services, presents fundamentally different challenges compared to user browsing. Understanding these differences is crucial for implementing effective security controls without unnecessary complexity or risk.

Not all FQDN filters are built the same.

I recently went down the AWS Gateway Load Balancer rabbit hole, and I've found it to be an interesting solution to some quite specific problems. There are use cases for it on ingress and egress where regulatory requirements, or more likely legacy skillsets, dictate that traffic passes through NVA-based network security appliances. The problem with NVAs in AWS is often the difficulty in scaling them. You need to distribute traffic, and typically you need a load balancer, but you can't use an ALB or an NLB because unlike Azure, the load balancers in AWS don't allow for traffic routing, so they can't be targets for route tables in the same way Azure load balancers can be targets for UDRs.