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Enterprise network security is typically reactive, and it relies heavily on host security and middleboxes. This approach creates complicated interactions between protocols and systems that can cause incorrect behavior and slow response to attacks. We argue that imbuing the network layer with mechanisms for dynamic access control can remedy these ills. We(More)
The Dynamic Host Configuration Protocol (DHCP) is used to dynamically allocate address space to hosts on a local area network. Despite its widespread usage, few studies exist on DHCP usage patterns, and even less is known about the importance of setting the lease time (the time that a client retains ownership over some IP address) to an appropriate value.(More)
Network conditions are dynamic; unfortunately, current approaches to configuring networks are not. Network operators need tools to express how a network's data-plane behavior should respond to a wide range of events and changing conditions, ranging from unexpected failures to shifting traffic patterns to planned maintenance. Yet, to update the network(More)
BGP severely constrains how networks can deliver traffic over the Internet. Today's networks can only forward traffic based on the destination IP prefix, by selecting among routes offered by their immediate neighbors. We believe Software Defined Networking (SDN) could revolutionize wide-area traffic delivery, by offering direct control over(More)
We present a new line of research investigating on-line adaptive reactive control mechanisms for autonomous intelligent agents. We discuss a case-based method for dynamic selection and modification of behavior assemblages for a navigational system. The case-based reasoning module is designed as an addition to a traditional reactive control system, and(More)
We describe a reactive robotic control system which incorporates aspects of machine learning to improve the system's ability to successfully navigate in unfamiliar environments. This system overcomes limitations of completely reactive systems by exercising on-line performance enhancement without the need for high level planning. The results of extensive(More)
—This paper surveys our ongoing work on the use of software-defined networking to simplify two acute policy problems in campus and enterprise network operations: access control and information flow control. We describe how the current coupling of high-level policy with low-level configuration makes these problems challenging today. We describe the specific(More)
The recent growth in use of the WorldWide Web in the Internet has caused a significant increase in the demand placed on Web servers. This increased load results in noticeably longer response times for users. We propose an approach to using multicast in the delivery of Web resources that reduces the load on servers as well as the networks that connect them.(More)
We describe a mobile application for social networking that demonstrates the features of <i>DTN#</i>, a .Net-based implementation of the DTN bundle specification and testbed for research in challenged networks. The application, dubbed D-Book, includes the ability for users to create, modify, and share profiles much like the popular web-based social(More)
A signiicant obstacle to achieving heterogeneous system interconnection is the need to maintain compatible network protocols on all communicating systems. Protocol standardization and prooling has long been viewed as a way to overcome this obstacle. The exclusive nature of this approach, however, presents certain limitations. Among them are exclusion of(More)