Abstract DNS is one of the core building blocks of the Internet. In this paper, we investigate DNS resolution in a strict IPv6-only scenario and find that a substantial fraction of zones cannot be resolved. We point out, that the presence of an resource record for a zone’s nameserver does not necessarily imply that it is resolvable in an IPv6-only environment since the full DNS delegation chain must resolve via IPv6 as well. Hence, in an IPv6-only setting zones may experience an effect similar to what is commonly referred to as lame delegation. Our longitudinal study shows that the continuing centralization of the Internet has a large impact on IPv6 readiness, i.e., a small number of large DNS providers has, and still can, influence IPv6 readiness for a large number of zones. A single operator that enabled IPv6 DNS resolution–by adding IPv6 glue records–was responsible for around 20.3% of all zones in our dataset not resolving over IPv6 until January 2017. Even today, 10% of DNS operators are responsible for more than 97.5% of all zones that do not resolve using IPv6 .

With the recent IPv4 address exhaustion, many networks can no longer rely on requesting additional IPv4 addresses space. They resort to new ways to obtain addresses: buying and leasing. In this paper, we first shed light on the recent economic trends of the IPv4 buying market by augmenting transfer statistics with public and private pricing information from four large IPv4 brokers. We infer the size of the IPv4 leasing market through two different data sources: routing information observed from BGP collectors and RDAP databases operated by the Regional Internet Registries. We find that neither of those sources alone is capable of estimating the full market size. We relate our findings to discussions with 13 IPv4 brokers and summarize how networks handle their demand for obtaining IPv4 addresses in 2020.

Due to the COVID-19 pandemic, many governments imposed lock-downs that forced hundreds of millions of citizens to stay at home. The implementation of confinement measures increased Internet traffic demands of residential users, in particular, for remote working, entertainment, commerce, and education, which, as a result, caused traffic shifts in the Internet core.

IP traffic with forged source addresses (i.e., spoofed traffic) enables a series of threats ranging from the impersonation of remote hosts to massive denial-of-service attacks. Consequently, IP address spoofing received considerable attention with efforts to either suppress spoofing, to mitigate its consequences, or to actively measure the ability to spoof in individual networks. However, as of today, we still lack a comprehensive understanding both of the prevalence and the characteristics of spoofed traffic "in the wild" as well as of the networks that inject spoofed traffic into the Internet.