Building network automation solutions

9 module online course

Start now!

Category: cloud

Availability Zones and Regions in AWS, Azure and GCP

My friend Daniel Dib sent me this interesting question:

As I understand it, subnets in Azure span availability zones. Do you see any drawback to this? Does subnet matter if your VMs are in different AZs?

I’m positive I don’t have to tell you what networks, subnets, and VRFs are, but you might not have worked with public cloud availability zones before. Before going into the details of Daniel’s question (and it will take us three blog posts to get to the end), let’s introduce regions and availability zones (you’ll find more details in AWS Networking and Azure Networking webinars).

read more add comment

Deploying Advanced AWS Networking Features

Miha Markočič created sample automation scripts (mostly Terraform configuration files + AWS CLI commands where needed) deploying these features described in AWS Networking webinar:

To recreate them, clone the GitHub repository and follow the instructions.

add comment

Worth Reading: Cloud Complexity Lies

Anyone who spent some time reading cloud providers' documentation instead of watching slide decks or vendor keynotes knows that setting up infrastructure in a public cloud is not much simpler than doing it on-premises. You will outsource hardware management (installations, upgrades, replacements…) and might deal with an orchestration system provisioning services instead of configuring individual devices, but you still have to make the same decisions, and take the same set of responsibilities.

Obviously that doesn’t look good in a vendor slide deck, so don’t expect them to tell you the gory details (and when they start talking about the power of declarative API you know you have a winner)… but every now and then someone decides to point out the state of emperor’s clothes, this time Gerben Wierda in his The many lies about reducing complexity part 2: Cloud.

For public cloud networking details, check out our cloud webinars and online course.

add comment

Why Is Public Cloud Networking So Different?

A while ago (eons before AWS introduced Gateway Load Balancer) I discussed the intricacies of AWS and Azure networking with a very smart engineer working for a security appliance vendor, and he said something along the lines of “it shows these things were designed by software developers – they have no idea how networks should work.

In reality, at least some aspects of public cloud networking come closer to the original ideas of how IP and data-link layers should fit together than today’s flat earth theories, so he probably wanted to say “they make it so hard for me to insert my virtual appliance into their network.

read more see 1 comments

Renumbering Public Cloud Address Space

Got this question from one of the networking engineers “blessed” with rampant clueless-rush-to-the-cloud.

I plan to peer multiple VNet from different regions. The problem is that there is not any consistent deployment in regards to the private IP subnets used on each VNet to the point I found several of them using public IP blocks as private IP ranges. As far as I recall, in Azure we can’t re-ip the VNets as the resource will be deleted so I don’t see any other option than use NAT from offending VNet subnets to use my internal RFC1918 IPv4 range. Do you have a better idea?

The way I understand Azure, while you COULD have any address range configured as VNet CIDR block, you MUST have non-overlapping address ranges for VNet peering.

read more add comment

Worth Reading: The Shared Irresponsibility Model in the Cloud

A long while ago I wrote a blog post along the lines ofit’s ridiculous to allow developers to deploy directly to a public cloud while burdening them with all sorts of crazy barriers when deploying to an on-premises infrastructure,” effectively arguing for self-service approach to on-premises deployments.

Not surprisingly, the reality is grimmer than I expected (I’m appalled at how optimistic my predictions are even though I always come across as a die-hard grumpy pessimist), as explained in The Shared Irresponsibility Model in the Cloud by Dan Hubbard.

For more technical details, watch cloud-focused ipSpace.net webinars, in particular the Cloud Security one.

see 1 comments

Automation Win: Recreating Cisco ACI Tenants in Public Cloud

This blog post was initially sent to the subscribers of our SDN and Network Automation mailing list. Subscribe here.

Most automation projects are gradual improvements of existing manual processes, but every now and then the stars align and you get a perfect storm, like what Adrian Giacommetti encountered during one of his automation projects.

The customer had well-defined security policies implemented in Cisco ACI environment with tenants, endpoint groups, and contracts. They wanted to recreate those tenants in a public cloud, but it took way too long as the only migration tool they had was an engineer chasing GUI screens on both platforms.

read more see 2 comments

New: AWS Networking Update

In last week’s update session we covered the new features AWS introduced since the creation of AWS Networking webinar in 2019:

  • AWS Local Zones, Wavelengths, and Outposts
  • VPC Sharing
  • Bring Your Own Addresses
  • IP Multicast support
  • Managed Prefix Lists in security groups and route tables
  • VPC Traffic Mirroring
  • Web Application Firewall
  • AWS Shield
  • VPC Ingress Routing
  • Inter-region VPC peering with Transit Gateways

The videos are already online; you need Standard or Expert ipSpace.net subscription to watch them.

add comment

EVPN Control Plane in Infrastructure Cloud Networking

One of my readers sent me this question (probably after stumbling upon a remark I made in the AWS Networking webinar):

You had mentioned that AWS is probably not using EVPN for their overlay control-plane because it doesn’t work for their scale. Can you elaborate please? I’m going through an EVPN PoC and curious to learn more.

It’s safe to assume AWS uses some sort of overlay virtual networking (like every other sane large-scale cloud provider). We don’t know any details; AWS never felt the need to use conferences as recruitment drives, and what little they told us at re:Invent described the system mostly from the customer perspective.

read more see 3 comments

Public Cloud Providers and IPv4 Address Space

When planning to move your workloads to a public cloud you might want to consider the minor detail of public IPv4 connectivity (I know of at least one public cloud venture that couldn’t get their business off the ground because they couldn’t get enough public IPv4 addresses).

Here’s a question along these lines that one of the attendees of our public cloud networking course sent me:

read more add comment

Example: Securing AWS Deployment

Nadeem Lughmani created an excellent solution for the securing your cloud deployment hands-on exercise in our public cloud online course. His Terraform-based solution includes:

  • Security groups to restrict access to web server and SSH bastion host;
  • An IAM policy and associated user that has read-only access to EC2 and VPC resources (used for monitoring)
  • An IAM policy that has full access to as single S3 bucket (used to modify static content hosted on S3)
  • An IAM role for AWS CloudWatch logs
  • Logging SSH events from the SSH bastion host into CloudWatch logs.
add comment
Sidebar