The Internet has evolved greatly from its original incarnation. For instance, the vast majority of current Internet usage is data retrieval and service access, whereas the architecture was designed around host-to-host applications such as telnet and ftp. Moreover, the original Internet was a purely transparent carrier of packets, but now the various network stakeholders use middleboxes to improve security and accelerate applications. To adapt to these changes, we propose the Data-Oriented Network Architecture (DONA), which involves a clean-slate redesign of Internet naming and name resolution. Categories and Subject Descriptors C.2.5 [Computer-Communication Networks]: Local and Wide-

The Internet consists of thousands of independent domains with different, and sometimes competing, business interests. However, the current interdomain routing protocol (BGP) limits each router to using a single route for each destination prefix, which may not satisfy the diverse requirements of end users. Recent proposals for source routing offer an alternative where end hosts or edge routers select the end-to-end paths. However, source routing leaves transit domains with very little control and introduces difficult scalability and security challenges. In this paper, we present a multi-path interdomain routing protocol called MIRO that offers substantial flexibility, while giving transit domains control over the flow of traffic through their infrastructure and avoiding state explosion in disseminating reachability information. In MIRO, routers learn default routes through the existing BGP protocol, and arbitrary pairs of domains can negotiate the use of additional paths (bound to tunnels in the data plane) tailored to their special needs. MIRO retains the simplicity of BGP for most traffic, and remains backwards compatible with BGP to allow for incremental deployability. Experiments with Internet topology and routing data illustrate that MIRO offers tremendous flexibility for path selection with reasonable overhead.

This paper presents the design, implementation, analysis, and experimental evaluation of speak-up, a defense against applicationlevel distributed denial-of-service (DDoS), in which attackers cripple a server by sending legitimate-looking requests that consume computational resources (e.g., CPU cycles, disk). With speak-up, a victimized server encourages all clients, resources permitting, to automatically send higher volumes of traffic. We suppose that attackers are already using most of their upload bandwidth so cannot react to the encouragement. Good clients, however, have spare upload bandwidth and will react to the encouragement with drastically higher volumes of traffic. The intended outcome of this traffic inflation is that the good clients crowd out the bad ones, thereby capturing a much larger fraction of the server’s resources than before. We experiment under various conditions and find that speak-up causes the server to spend resources on a group of clients in rough proportion to their aggregate upload bandwidth. This result makes the defense viable and effective for a class of real attacks.

Connectivity in today’s enterprise networks is regulated by a combination of complex routing and bridging policies, along with various interdiction mechanisms such as ACLs, packet filters, and other middleboxes that attempt to retrofit access control onto an otherwise permissive Internet architecture. This leads to enterprise networks that are inflexible, fragile and difficult to manage. We offer SANE, a protection architecture for enterprise networks that overcomes these limitations. By default, hosts can only contact a logically centralized reference monitor that hands out capabilities (encrypted source routes) for services, according to declarative access control policies (e.g. Alice can access

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Systems using capabilities to provide preferential service to selected flows have been proposed as a defense against large-scale network denial-of-service attacks. While these systems offer strong protection for established network flows, the Denial-of-Capability (DoC) attack, which prevents new capability-setup packets from reaching the destination, limits the value of these systems. Portcullis mitigates DoC attacks by allocating scarce link bandwidth for connection establishment packets based on per-computation fairness. We prove that a legitimate sender can establish a capability with high probability regardless of an attacker’s resources or strategy and that no system can improve on our guarantee. We simulate full and partial deployments of Portcullis on an Internetscale topology to confirm our theoretical results and demonstrate the substantial benefits of using per-computation fairness.

Many Denial of Service attacks use brute-force bandwidth flooding of intended victims. Such volume-based attacks aggregate at a target’s access router, suggesting that (i) detection and mitigation are best done by providers in their networks; and (ii) attacks are most readily detectable at access routers, where their impact is strongest. In-network detection presents a tension between scalability and accuracy. Specifically, accuracy of detection dictates fine grained traffic monitoring, but performing such monitoring for the tens or hundreds of thousands of access interfaces in a large provider network presents serious scalability issues. We investigate the design space for in-network DDoS detection and propose a triggered, multi-stage approach that addresses both scalability and accuracy. Our contribution is the design and implementation of LADS (Large-scale Automated DDoS detection System). The attractiveness of this system lies in the fact that it makes use of data that is readily available to an ISP, namely, SNMP and Netflow feeds from routers, without dependence on proprietary hardware solutions. We report our experiences using LADS to detect DDoS attacks in a tier-1 ISP. 1

We argue that the current model for flow establishment in the Internet: DNS Names, IP addresses, and transport ports, is inadequate due to problems that go beyond the small IPv4 address space and resulting NAT boxes. Even where global addresses exist, firewalls cannot glean enough information about a flow from packet headers, and so often err, typically by being over-conservative: disallowing flows that might otherwise be allowed. This paper presents a novel architecture, protocol design, and implementation, for flow establishment in the Internet. The architecture, called NUTSS, takes into account the combined policies of endpoints and network providers. While NUTSS borrows liberally from other proposals (URI-like naming, signaling to manage ephemeral IPv4 or IPv6 data flows), NUTSS is unique in that it couples overlay signaling with data-path signaling. NUTSS requires no changes to existing network protocols, and combined with recent NAT traversal techniques, works with IPv4 and existing NAT/firewalls. This paper describes NUTSS and shows how it satisfies a wide range of “end-middle-end” network requirements, including access control, middlebox steering, multi-homing, mobility, and protocol negotiation.

A key challenge in combating Denial of Service (DoS) attacks is to reliably identify attack sources from packet contents. If a source can be reliably identified, routers can stop an attack by filtering packets from the attack sources without causing collateral damage to legitimate traffic. This task is difficult because attackers may spoof arbitrary packet contents to hide their identities. This paper proposes a packet passport system to address this challenge. A packet passport efficiently and securely authenticates the source of a packet. A packet with a valid passport must have originated from the claimed source. The packet passport system can be incrementally deployed without introducing extra control messages. It also provides incentives for early adoption: a domain that deploys packet passport system can prevent other domains from spoofing its source identifiers. Our preliminary analysis suggests that the packet passport system can be implemented at high-speed routers with today’s technologies. 1

Today’s cloud-based services integrate globally distributed resources into seamless computing platforms. Provisioning and accounting for the resource usage of these Internet-scale applications presents a challenging technical problem. This paper presents the design and implementation of distributed rate limiters, which work together to enforce a global rate limit across traffic aggregates at multiple sites, enabling the coordinated policing of a cloud-based service’s network traffic. Our abstraction not only enforces a global limit, but also ensures that congestion-responsive transport-layer flows behave as if they traversed a single, shared limiter. We present two designs—one general purpose, and one optimized for TCP—that allow service operators to explicitly trade off between communication costs and system accuracy, efficiency, and scalability. Both designs are capable of rate limiting thousands of flows with negligible overhead (less than 3 % in the tested configuration). We demonstrate that our TCP-centric design is scalable to hundreds of nodes while robust to both loss and communication delay, making it practical for deployment in nationwide service providers.