Fixing ally's growing pains with velocity modeling

Abstract

Mapping the router topology is an important component of Internet measurement. Alias resolution, the process of mapping IP addresses to routers, is critical to accurate Internet mapping. Ally, a popular alias resolution tool, was developed to resolve aliases in individual ISPs, but its probabilistic accuracy and need to send O(n 2 ) probes to infer aliases among n IP addresses make it unappealing for large-scale Internet mapping. In this paper, we present RadarGun, a tool that uses IP identifier velocity modeling to improve the accuracy and scalability of the Ally-based resolution technique. We provide analytical bounds on Ally's accuracy and validate our predicted aliases against Ally. Additionally, we show that velocity modeling requires only O(n) probes and thus scales to Internet-sized mapping efforts.

Measuring and Characterizing IPv6 Router Availability

“…While similar IP-ID behavior is found in IPv4 routers, there are three important differences. First, the IPID counter behavior in IPv4 is much more erratic because routers increment the ID counter every time they create a packet, causing the counter's velocity to be large for routers with chatty routing protocols or SNMP reporting [1,13]. Second, the counter itself only has a range of 65536 values, requiring more frequent probing than in IPv6 to prevent a counter wrap from being interpreted as a reboot.…”

Toward Topology Dualism: Improving the Accuracy of AS Annotations for Routers

“…MIDAR expands on the IP velocity techniques of RadarGun [8], and kapar expands on the analytical techniques of APAR [14]. We first use the traceroute dataset as input to MIDAR, the output of which is fed into kapar.…”

Topology Discovery at the Router Level: A New Hybrid Tool Targeting ISP Networks

“…Interested readers may find explanations about those values in [21]. The collected topologies are publicly available to the research community 9 .…”

“…If this set contains n IP addresses at the end of the probing period, and since we perform an almost brute force approach, the required time complexity is in ≈ n×(n−1) 2 . Note that generally, for large ASes, this period may represent about 40% of the total time required by MERLIN but may be strongly reduced using recent improvements in the alias resolution field [9]. Fig.…”

“…While the two first levels do not require to find which IP interfaces belong to a given router, router level topology discovery usually relies on alias resolution techniques [6], [9], [10], [11]. This process is known as quite intrusive and/or resource consuming whereas it suffers from several bias.…”