VM BPDU spoofing attack works quite nicely in HA clusters

When I wrote the Virtual switches need BPDU guard blog post, I speculated that you could shut down a whole HA cluster with a single BPDU-generating VM ... and got a nice confirmation during the Troopers 13 conferenceERNW specialists successfully demonstrated the attack while testing the security aspects of a public cloud implementation for a major service provider.

For more information, read their blog post (they also have a nice presentation explaining how a VM can read ESXi hard drive with properly constructed VMDK file).

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This Is What Makes Networking So Complex

The responses to my What did you do to get rid of manual VLAN provisioning post were easy to predict: a few people sharing their best practices (thank you!), few musings on the future of SDN/networking, and the ubiquitous anonymous rant against stubbornness and stupidity of networking engineers and their OPEX.

I know one should never feed anonymous trolls, but this morsel is simply too juicy to pass, so here it is – let’s see what makes networking so complex.

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Compromised Security Zone = Game Over (Or Not?)

Kevin left a pretty valid comment to my Are you ready to change your security paradigm blog post:

I disagree that a compromised security zone is game over. Security is built in layers. Those host in a compromised security zone should be hardened, have complex authentication requirements to get in them, etc. Just because a compromised host in a security zone can get at additional ports on the other hosts doesn't mean an attacker will be more successful.

He’s right from the host-centric perspective (assuming you actually believe those other hosts are hardened), but once you own a server in a security zone you can start having fun with intra-subnet attacks.

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Kickstart free CCNA and CCNP videos!

Andrew Crouthamel had a great idea – he decided to produce free CCNA-level videos and started a Kickstart campaign to get the funding. The initial response was overwhelming, so he included stretch goals: Wireshark training (WCNA – already reached) and CCNP.

He probably underestimated the costs of the project, but that doesn’t really matter. I’m positive he’ll deliver, so let’s help him get started – if only 10% of my readers donate a single morning Frapuccino to his project, he’ll have more than enough funding to get the whole CCNP curriculum done.

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464XLAT Explained

IETF recently published RFC 6877 (464XLAT) describing a dual-translation mechanism that allows an IPv6 host (or CPE) in an IPv6-only access network to pretend it still has IPv4 connectivity. Why would one need a kludge ingenious solution like this? In a word: Skype.

For more details, watch the video explaining the need for 464XLAT and two typical use cases: Android handset and a CPE device (example: SOHO router with 3G uplink).

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