IPv6 Security

Terry Slattery
Principal Architect

One of the security factors I’ve heard espoused about IPv6 is that the large address space (128 bits: 64 bits of network and 64 bits of host address) makes it impossible to scan the network for hosts. On initial inspection, this seemed like a reasonable thought.

However, when you look at IPv6’s use of multicast for router and route prefix discovery, the security advantage doesn’t make as much sense. Nothing prevents a system from monitoring the multicast address and collecting information about other systems on the local subnet. Since the networks of small companies and home networks are typically a single subnet, this approach works well for finding other local systems.

But what about remote subnets? Doesn’t the large address space help reduce scanning there? It sure does. However, it doesn’t inhibit the exploitation of peer relationships. Think of the addresses of the application servers known by the end stations on your network. Another source is the IP addresses contained in email headers. Overall, I see that there is still a reasonably rich set of address data that can be harvested through other mechanisms.

I predict that the black hat community will quickly find these and other sources of addresses to replace address space scanning techniques. Defense in depth is the only viable recourse.



Re-posted with Permission 

NetCraftsmen would like to acknowledge Infoblox for their permission to re-post this article which originally appeared in the Applied Infrastructure blog under http://www.infoblox.com/en/communities/blogs.html


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Nick Kelly

Cybersecurity Engineer, Cisco

Nick has over 20 years of experience in Security Operations and Security Sales. He is an avid student of cybersecurity and regularly engages with the Infosec community at events like BSides, RVASec, Derbycon and more. The son of an FBI forensics director, Nick holds a B.S. in Criminal Justice and is one of Cisco’s Fire Jumper Elite members. When he’s not working, he writes cyberpunk and punches aliens on his Playstation.


Virgilio “BONG” dela Cruz Jr.

CCDP, CCNA V, CCNP, Cisco IPS Express Security for AM/EE
Field Solutions Architect, Tech Data

Virgilio “Bong” has sixteen years of professional experience in IT industry from academe, technical and customer support, pre-sales, post sales, project management, training and enablement. He has worked in Cisco Technical Assistance Center (TAC) as a member of the WAN and LAN Switching team. Bong now works for Tech Data as the Field Solutions Architect with a focus on Cisco Security and holds a few Cisco certifications including Fire Jumper Elite.


John Cavanaugh

CCIE #1066, CCDE #20070002, CCAr
Chief Technology Officer, Practice Lead Security Services, NetCraftsmen

John is our CTO and the practice lead for a talented team of consultants focused on designing and delivering scalable and secure infrastructure solutions to customers across multiple industry verticals and technologies. Previously he has held several positions including Executive Director/Chief Architect for Global Network Services at JPMorgan Chase. In that capacity, he led a team managing network architecture and services.  Prior to his role at JPMorgan Chase, John was a Distinguished Engineer at Cisco working across a number of verticals including Higher Education, Finance, Retail, Government, and Health Care.

He is an expert in working with groups to identify business needs, and align technology strategies to enable business strategies, building in agility and scalability to allow for future changes. John is experienced in the architecture and design of highly available, secure, network infrastructure and data centers, and has worked on projects worldwide. He has worked in both the business and regulatory environments for the design and deployment of complex IT infrastructures.