Category: security

Automatic Clean-and-Updated Firewall Ruleset

This is a guest blog post by Andrea Dainese, senior network and security architect, and author of UNetLab (now EVE-NG) and  Route Reflector Labs. These days you’ll find him busy automating Cisco ACI deployments.


Following the Ivan’s post about Firewall Ruleset Automation, I decided to take a step forward: can we always have up-to-date and clean firewall policies without stale rules?

The problem

We usually configure and manage firewalls using a process like this:

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Stateful Firewalls: When You Get to a Fork in the Road, Take It

If you’ve been in networking long enough you’d probably noticed an interesting pattern:

  • Some topic is hotly debated;
  • No agreement is ever reached even though the issue is an important one;
  • The debate dies after participants diverge enough to stop caring about the other group.

I was reminded of this pattern when I was explaining the traffic filtering measures available in private and public clouds during the Designing Infrastructure for Private Clouds workshop.

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Worth Reading: Blockchain and Trust

One of the rules of sane social media presence should be don’t ever engage with evangelists believing in a particular technology religion, more so if their funding depends on them spreading the gospel. I was called old-school networking guru from ivory tower when pointing out the drawbacks of TRILL, and clueless incompetent (in more polite words) when retweeting a tweet pointing out the realities of carbon footprint of proof-of-work technologies.

Interestingly, just a few days after that Bruce Schneier published a lengthy essay on blockchain and trust, and even the evangelists find it a bit hard to call him incompetent on security topics. Please read what he wrote every time someone comes along explaining how blockchains will save the world (or solve whatever networking problems like VTEP-to-MAC mappings).

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OMG, VXLAN Is Still Insecure

A friend of mine told me about a “VXLAN is insecure, the sky is falling” presentation from RIPE-77 which claims that you can (under certain circumstances) inject packets into VXLAN virtual networks from the Internet.

Welcome back, Captain Obvious. Anyone looking at the VXLAN packet could immediately figure out that there’s no security in VXLAN. I pointed that out several times in my blog posts and presentations, including Cloud Computing Networking (EuroNOG, September 2011) and NSX Architecture webinar (August 2013).

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MUST READ: Operational Security Considerations for IPv6 Networks

A team of IPv6 security experts I highly respect (including my good friends Enno Rey, Eric Vyncke and Merike Kaeo) put together a lengthy document describing security considerations for IPv6 networks. The document is a 35-page overview of things you should know about IPv6 security, listing over a hundred relevant RFCs and other references.

No wonder enterprise IPv6 adoption is so slow – we managed to make a total mess.

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Integrating 3rd Party Firewalls with Amazon Web Services (AWS) VPC Networking

After figuring out how packet forwarding really works within AWS VPC (here’s an overview, the slide deck is already available to ipSpace.net subscribers) the next obvious question should be: “and how do I integrate a network services device like a next-generation firewall I have to use because $securityPolicy into that environment?

Please don’t get me started on whether that makes sense, that’s a different discussion.

Christer Swartz, an old-time CCIE and occasional guest on Software Gone Wild podcast will show you how to do it with a Palo Alto firewall during my Amazon Web Services Networking Deep Dive workshop on June 13th in Zurich, Switzerland (register here).

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Container Security through Segregation

One of my readers sent me a container security question after reading the Application Container Security Guide from NIST:

We are considering segregating dev/test/prod environments with bare-metal hardware. I did not find something in the standard concerning this. What should a financial institution do in your opinion?

I am no security expert and know just enough about containers to be dangerous, but there’s a rule that usually works well: use common sense and identify similar scenarios that have already been solved.

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I Can’t Choose the Gear for You

One of my readers sent me a question along these lines after reading the anti-automation blog post:

Your blog post has me worried as we're currently reviewing offers for NGFW solution... I understand the need to keep the lid on the details rather than name and shame, but is it possible to get the details off the record?

I always believed in giving my readers enough information to solve their challenges on their own (you know, the Teach a man to fish idea).

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Reinventing SSL VPN (RFC 1925 Strikes Again)

Some of my readers got annoyed when I mentioned Google’s BeyondCorp and RFC 1925 in the same sentence (to be perfectly clear, I had Rule#11 in mind). I totally understand that sentiment – reading the reactions from industry press it seems to be the best thing that happened to Enterprise IT in decades.

Let me explain in simple terms why I think it’s not such a big deal and definitely not something new, let alone revolutionary.

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