Research: BGP Routers and Parrots
The BGP specification suggests implementations should have three tables: the adj-rib-in, the loc-rib, and the adj-rib-out. The first of these three tables should contain the routes (NLRIs and attributes) transmitted by each of the speaker’s peers. The second table should contain the calculated best paths; these are the routes that will be (or are) installed…
CAA Records and Site Security
The little green lock—now being deprecated by some browsers—provides some level of comfort for many users when entering personal information on a web site. You probably know the little green lock means the traffic between the host and the site is encrypted, but you might not stop to ask the fundamental question of all cryptography:…
Research: Measuring IP Liveness
Of the 4.2 billion IPv4 addresses available in the global space, how many are used—or rather, how many are “alive?” Given the increasing usage of IPv6, it might seem this is an unimportant question. Answering the question, however, resolves to another question that is actually more important: how can you determine whether or not an…
BGP Hijacks: Two more papers consider the problem
The security of the global Default Free Zone DFZ) has been a topic of much debate and concern for the last twenty years (or more). Two recent papers have brought this issue to the surface once again—it is worth looking at what these two papers add to the mix of what is known, and what…
Ossification and Fragmentation: The Once and Future ‘net
Mostafa Ammar, out of Georgia Tech (not my alma mater, but many of my engineering family are alumni there), recently posted an interesting paper titled The Service-Infrastructure Cycle, Ossification, and the Fragmentation of the Internet. I have argued elsewhere that we are seeing the fragmentation of the global Internet into multiple smaller pieces, primarily based…
IPv6 Security Considerations
When rolling out a new protocol such as IPv6, it is useful to consider the changes to security posture, particularly the network’s attack surface. While protocol security discussions are widely available, there is often not “one place” where you can go to get information about potential attacks, references to research about those attacks, potential counters,…
BGP Security: A Gentle Reminder that Networking is Business
At NANOG on the Road (NotR) in September of 2018, I participated in a panel on BGP security—specifically the deployment of Route Origin Authentication (ROA), with some hints and overtones of path validation by carrying signatures in BGP updates (BGPsec). This is an area I have been working in for… 20 years? … at this…
Research: Tail Attacks on Web Applications
When you think of a Distributed Denial of Service (DDoS) attack, you probably think about an attack which overflows the bandwidth available on a single link; or overflowing the number of half open TCP sessions a device can have open at once, preventing the device from accepting more sessions. In all cases, a DoS or…
Research: DNSSEC in the Wild
The DNS system is, unfortunately, rife with holes like Swiss Cheese; man-in-the-middle attacks can easily negate the operation of TLS and web site security. To resolve these problems, the IETF and the DNS community standardized a set of cryptographic extensions to cryptographically sign all DNS records. These signatures rely on public/private key pairs that are…
Why is the Feasibility Condition Less Than?
A reader recently emailed me with this question: Why isn’t the condition for a Feasible Successor set to less than (B. D will immediately reroute to the FS, which is C, without changing the FC. This works, because C’s cost to 100::/64 via D is 4, much higher than it’s cost to 100::64 along C->A.…