Azure networking limitations

I’m currently involved in a project to move a data centre to ‘the cloud’. For commercial reasons, Azure was the chosen platform and I had been tasked with evaluating the networking capability there. While Amazon AWS has the luxury of a few years head start, and a better adoption from most networking/security players, Azure is very immature in this area. There is currently only one firewall vendor that exists in Azure and this is Barracuda.

Some of the azure networking limitations which exist as of today (06/2014):

  • No network level ACL’s between guests in a single subnet. Any host in a subnet has free-for-all access to other guests in the same subnet. You cannot create VACL’s like you would in a traditional DMZ environment. If one machine is compromised, there’s a good chance others will go with it.
  • There is a big reliance on guest OS firewalling. All the technical guides suggest you use some sort of firewall on the guest OS itself. Generally, iptables for Linux, Windows Firewall for Windows OS. Other vendors are don’t seem to be recommended.
  • Access between virtual nets must use public endpoints. This means a public IP addresses and Natting. A pubic IP address may represent several guests within a group, so the actual source of the traffic is obfuscated. It means controlling this access is less granular.
  • No role based access – your platforms team have as much access to network changes as your network team does.
  • By default, guests have full bound outbound access if they are internet accessible (ie have at least one endpoint). Once again, a firewall on the guest OS must be used to restrict this.
  • No gateway changes – there is no way to add a new default route to route traffic through a particular networking device ie a firewall.
  • Only one NIC per guest, no internal/external NIC topology permitted.

My impression is that Azure are pretty proactive about the platform, it’s being improved constantly but the networking doesn’t seem to get much love. I’ll be doing a lot of work on this over the coming months so I’ll post more information as I discover it.

Have a look at the currently requested features, some of this stuff is networking 101 pretty much!

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