Protecting DNS from software errors

The ability to forward packets on the Internet is highly intertwined with the availability and robustness of the Domain Name System (DNS) infrastructure. Unfortunately, the DNS suffers from a wide variety of problems arising from implementation errors, including vulnerabilities, bogus queries, and proneness to failure. In this work, we present a preliminary design and early prototype implementation of a system that leverages diversified replication to increase tolerance of DNS to implementation errors. Our design leverages software diversity by running multiple redundant copies of software in parallel, and leverages data diversity by replicating requests to multiple redundant servers. Using traces of DNS queries, we demonstrate our design can keep up with the loads of a large university???s DNS traffic, while improving resilience to DNS???s availability problems

Better by a HAIR: Hardware-amenable internet routing

Abstract—Routing protocols are implemented in the form of software running on a general-purpose microprocessor. However, conventional software-based router architectures face significant scaling challenges in the presence of ever-increasing routing table growth and churn. Recent advances in programmable hardware and high-level hardware description languages provide the opportunity to implement BGP directly at the hardware layer. Hardware-based implementation allows designs to take advantage of the parallelization and customizability of the underlying hardware to improve performance. As a first step in this direction, we design and implement a hardware-based BGP architecture. To understand the challenges in doing this, we propose an architecture and logical design for the core components of BGP running as a logical circuit in an FPGA. We then enumerate sources of complexity and performance bottlenecks, and derive modifications to BGP that reduce com-plexity of hardware offloading. Our results based on update traces from core Internet routers indicate an order of magnitude improvement in processing time and throughput. I

SpectrUW: a laboratory for the numerical exploration of spectra of linear operators

Spectra of linear operators play an important role in various aspects of applied mathematics. For all but the simplest operators, the spectrum cannot be determined analytically and as such it is difficult to build up any intuition about the spectrum. One way to obtain such intuition is to consider many examples numerically and observe emerging patterns. This is feasible using an efficient black-box numerical method, i.e., a method that requires no conceptual changes for different examples. Hill’s method satisfies these requirements. It is the mathematical foundation of SpectrUW (pronounced “spectrum”), mathematical black-box software that serves as a laboratory for the numerical approximation of spectra of one-dimensional linear operators.

Genome-wide identification of the VOZ transcription factors in tomato (<i>Solanum lycopersicum</i>): their functions during fruit ripening and their responses to salinity stress

As a plant-specific transcription factor, vascular plant One-Zinc-finger (VOZ) is involved in the regulation of many biological processes. VOZ genes in tomato have not been analysed comprehensively so far. In this study, two SIVOZs were identified on a genome-wide scale in tomato and analysed using various bioinformatics methods. According to Ka/Ks ratio, SlVOZ proteins are being changed by evolutionary processes to adapt to changing growth and stress conditions. Protein structure and phylogenetic analyses also indicated that transcriptional regulations of SlVOZs were controlled in a specific manner related to developmental stages and abiotic stress conditions. Digital expression results, in particular, showed that SlVOZs are not only active during different growth status of tomato but are also involved in abiotic stress response mechanism. Nonetheless, SlVOZ1 is expressed higher in both developmental stages and under salt stress conditions, confirmed by RT-qPCR. The co-expression maps constructed using RNA-seq data showed that SlVOZ2 was associated with the genes involved in hormonal regulation, formation of fruit shape, secondary wall biosynthesis and in plant development. Overall, it can be concluded that SlVOZs are not only important for plant growth and development but may also be part of the salt stress response mechanism.</p