We consider DoS attacks on DNS where attackers flood the nameservers of a zone to disrupt resolution of resource records belonging to the zone and consequently, any of its sub-zones. We argue that a minor change in the caching behavior of DNS resolvers can significantly mitigate the impact of such attacks. In our proposal, DNS resolvers do not completely evict cached records whose TTL has expir...

OBJECTIVES To clarify potential differences between denosumab (DNS) and bisphosphonates (BIS) in terms of bone density and bone metabolism, in a sample of postmenopausal women. METHODS A total of 113 postmenopausal women aged 53-66 years were treated with either DNS or BIS for 12 months. Bone densitometry and laboratory tests were compared between baseline and follow-up. RESULTS Femoral nec...

BACKGROUND Dysplastic nodules (DNs) recently have been identified as preneoplastic lesions of hepatocellular carcinoma (HCC). To test an alternative hypothesis regarding DN development, in which we have suggested that DNs develop as an infiltrating clonal expansion in advance of, or parallel to cirrhosis, the authors investigated the rates of apoptosis and proliferation in human hepatocarcinoge...

DNS servers often fail or have bad implementations of algorithms that decrease the efficiency of the DNS system. We introduce a method for clustering misconfigured DNS sources. Using machine learning methods, we analyzed 24 hours of DNS requests that were collected on the A-root DNS server. The 50 gigabyte data set was a log containing 10-40 million requests per hour. We selected the hour of 1:...

To combat Domain Name System (DNS) cache poisoning attacks and exploitation of the DNS as amplifier in denial of service (DoS) attacks, many recursive DNS resolvers are configured as “closed” and refuse to answer queries made by hosts outside of their organization. In this work, we present a technique to induce DNS queries within an organization, using the organization’s email service and the S...

As the hidden backbone of today's Internet, the Domain Name System (DNS) provides name resolution service for almost every networked application. To exploit the rich DNS query information for traffic engineering or user behavior analysis, both passive capturing and active probing techniques have been proposed in recent years. Despite its full visibility of DNS behaviors, the passive capturing t...

On the net, close to everything starts with a request to the Domain Name System (DNS), a core Internet protocol to allow users to access Internet services by names, such as www.example.com, instead of using numeric IP addresses, like 2001:DB8:4145::4242. Developed in the “Internet good old times” the contemporary DNS is like a large network activity chart for the visually impaired. Consequently...

The botnet is considered as a critical issue of the Internet due to its fast growing mechanism and affect. Recently, Botnets have utilized the DNS and query DNS server just like any legitimate hosts. In this case, it is difficult to distinguish between the legitimate DNS traffic and illegitimate DNS traffic. It is important to build a suitable solution for botnet detection in the DNS traffic an...

We carried out an entropy study on the DNS query traffic from the Internet to the top domain DNS server in a university campus network through January 1st to March 31st, 2009. The obtained results are: (1) We observed a difference for the entropy changes among the total-, the A-, and the PTR resource records (RRs) based DNS query traffic from the Internet through January 17th to February 1st, 2...