Study on OSPF Algebraic Formal Modelling Using ACP

Link State Advertisement (LSA) reflects the current status of all incident links of a router in an Autonomous System (AS). A fake LSA with false link status information will pollute the view of the network topology on routers. In this paper, we present two novel attacks that inject malicious Link State Advertisements (LSAs) to modify the routing tables: adjacency spoofing and single path injection. Adjacency spoofing attack makes attacker access to routing networks by disguising as a legitimate router. Single path injection attack evades the “fight-back” mechanism and affects routing advertisements of routers. Unlike existing LSA injection attacks, which need to be launched by malicious routers, a common host can launch these attacks and control the transmission path of data traffic in an AS. Simulation and real-world experiment results show that these two attacks can efficiently modify the routing tables of routers, and further lead to DNS spoofing, phishing Website, eavesdropping, and manin-the-middle attacks. Furthermore, we also implement a security vulnerability detection system to detect the existing vulnerabilities of routing protocol deployed in real-world routers.

The first comparison of the performance of name-based content routing protocols based on distance vectors and link-states is presented. The protocols used for this comparison are the Named-data Link State Routing (NLSR) protocol, which is the main representative of name-based content routing based on link states, and the Distance-based Content Routing (DCR) protocol, which is the first name-based content routing protocol based on distance vectors. In the simulation of NLSR, the signaling of NLSR is simplified to minimize the overhead it incurs sending link state advertisements (LSAs), such that a single transmission is need to send an LSA, rather than multiple transmission as is the case with NLSR. The results of simulations show that the ideal version of NLSR requires fewer control messages to react to changes of name prefixes when the number of replicas is very small, and DCR incurs less signaling overhead to react to topology changes or changes in name prefixes when the number of replicas is large.

Alternating Bit Protocol (ABP) is a timeless communication protocol but it might be spiced up by adding up some time constraints to it. According to that, four cases have been defined herein and then, formal specifications and verifications have been performed in them following the rules of a process algebra called Algebra of Communicating Processes (ACP). Oftentimes process algebras lead to cumbersome calculations that are most frequently done by using specific software packages such as mCRL2 or LOTOS, which might lead to lose perspective on the basics. In this paper, a simplifying trick is presented in order to ease up those calculations, thus making easier a manual approach to ACP algebraic derivations and hence, helping a better understanding of them.

Current link-state routing protocols (e.g., OSPF) use flooding to disseminate link-state information throughout the network. Despite its simplicity and reliability, flooding incurs unnecessary communications overhead since nodes may receive multiple copies of the same advertisement. This extra overhead becomes an Issue in the context of quality-of-service (QoS) routing, where link state is and needs to be advertised frequently. The advertisement overhead can be significantly reduced by using tree-based broadcasting approaches. Although several of these approaches have been proposed in the literature, they are not used in practice because of their complexity and/or unreliability. We propose a new link-state dissemination approach that combines the best features of flooding and tree-based broadcasting. Our hybrid approach is particularly suited for dynamic link metrics (e.g., available bandwidth). It uses periodic flooding to advertise topology changes and first-time LSAs (link-state advertisements), and uses tree-based broadcasting to disseminate subsequent refresh LSAs. The broadcast trees in our approach are constructed dynamically during the flooding of the first LSA, without the need for the complex algorithms of previous tree-based approaches. Two versions of our dissemination approach are presented, with one being more suitable for networks with frequent topological changes. We prove the correctness of our approach and contrast its communications overhead with flooding and pure tree-based broadcasting. The results indicate that our hybrid approach has a significantly lower overhead than flooding; yet It enjoys the simplicity, reliability, and fast convergence of flooding. Finally, we outline how OSPF can be extended to support the proposed dissemination approach.

Link-state protocols such as OSPF are the dominant routing technology in today's Internet. Despite their many advantages, these protocols require the flooding of new information across the entire routing area after changes in any link state (e.g., link failures). As the routing area grows or the frequency of link-state changes increases, the overhead (in terms of bandwidth and processing cost) of flooding becomes prohibitive. Furthermore, such flooding over a large area will cause temporary inconsistency of link states among many routers, potentially creating many transient routing loops that can last for a long time. This limits the scalability of the routing protocols to large routing areas. To overcome such problems, we present in this paper a novel algorithm that minimizes the amount of information distributed by link-state routing protocols. Upon a link failure, our algorithm will distribute the link-state changes to the minimum number of routers that are needed to ensure loop-free routing. Moreover, implementing our algorithm requires only a simple extension to any existing link-state protocol.

Denial of service (DoS) attacks are a serious threat to the appropriate operation of services within network domains. In this paper, we propose a system that creates an overlay network to provide intra-domain IP traceback to deal with this threat. The Main contribution of our proposal with respect to previous work is its ability to provide partial and progressive deployment of the traceback system throughout a monitored network domain. We build the overlay network using the OSPF routing protocol through the creation of an IP Traceback Opaque LSA (Link State Advertisement). We also investigate and evaluate the performance of partial and progressive deployment of the proposed system, showing its suitability even for large network domains.

In this paper, a new service oriented networking paradigm is presented, where network nodes (peers) are self- organized into individual service entities. The key idea relies on the overlay approach, where there exists a virtual service plane, fragmented into self-organized and self-managed entities called islands of service transparency. The islands are formed in an upstream, ad-hoc mode from the non-networking resources (i.e VoD, grid server, etc) towards all ingress routers of the network, using link state advertisements and multi-cost path selection algorithms (i.e residual bandwidth, server capacity, storage, etc). Organization and re-organization of nodes around non-network resources is transparent to end-users, and thus any request within a specific service island is transparently routed to the island's resource for execution. A service proxy is commissioned to resolve service addresses and service attributes to QoS metrics. In this paper, we present the main notations and metrics of the proposed architecture as well as node behavior and potential GMPLS extensions for implementation issues.

This document recommends methods that are intended to improve the scalability and stability of large networks using Open Shortest Path First (OSPF) Version 2 protocol. The methods include processing OSPF Hellos and Link State Advertisement (LSA) Acknowledgments at a higher priority compared to other OSPF packets, and other congestion avoidance procedures. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements.

Every so often it helps to go back to the beginning and remind ourselves of the purpose of our efforts.

Routing protocols based on the link-state paradigm notoriously suffer from the problem of stale information in highly dynamic traffic scenarios, leading to an overall loss in routing efficiency. Solutions are not easy to come by, since an increase in the frequency of link state advertisements is equally dangerous: route flapping (i.e., periodic route changes that force traffic to be routed through an alternately underloaded set of paths) is one of the main drawbacks. In this paper we propose a novel, yet simple link state mechanism that may deliberately advertise false link state information with the purpose of stabilizing the routing, while keeping a high network utilization

A mobile ad-hoc network (MANET) is basically called as a network without any central administration or fixed infrastructure. It consists of a number of mobile nodes that use to send data packets through a wireless medium. There is always a need of a good routing protocol in order to establish the connection between mobile nodes since they possess the property of dynamic changing topology. Further, in all the existing routing protocols, mobility of a node has always been one of the important characteristics in determining the overall performance of the ad hoc network. Thus, it is essential to know about various mobility models and their effect on the routing protocols. In this paper, we have made an attempt to compare different mobility models and provide an overview of their current research status. The main focus is on Random Mobility Models and Group Mobility Models. Firstly, we present a survey of the characteristics, drawbacks and research challenges of mobility modeling. At the last we present simulation results that illustrate the importance of choosing a mobility model in the simulation of an ad hoc network protocol. Also, we illustrate how the performance results of an ad hoc network protocol drastically change as a result of changing the mobility model simulated.

This paper presents the design of Directed-Propagation Link-State Routing Protocol (DPLSR), which tries to address the issue of prefix flooding storm in NDN Link-state Routing Protocol. Since the number of data object is several order of magnitude of that of routers, legacy Link State Advertisements (LSAs) flooding model is no more appropriate in NDN. This paper proposes a LSA directed-propagation scheme that LSA messages are only forwarded towards Root anchor, not flooding. Upon requesting a data object, a Look-up message is sent towards Root anchor. When it encounters a router with accroding anchor and prefix information, an anchor list is returned. Users are able to access the nearest copy or build one or multi-path connections to the anchors. In DPLSR, messages are propagated along some paths, and only parts of router store prefix and anchor information. Thus, the communication overhead and prefix storage are reduced significantly compared with the existing NDN routing protocols. Simulated experiments also verifies the performance gain of DPLSR.

This document describes the OSPFv3 graceful restart. The OSPFv3 graceful restart is identical to OSPFv2 except for the differences described in this document. These differences include the format of the grace Link State Advertisements (LSA) and other considerations.

Although several theoretical models for links and routes selection have been proposed in the literature, little effort has been made to apply them to routing protocols. In this paper a decision tree has been incorporated into the routing protocol in order to select the most long-lived routes. The decision tree is based on several assumptions which take into account the most relevant parameters considered by the theoretical models, such as distance between nodes, relative speed, and nodes' directions. The proposed approach has been implemented over a reactive routing protocol as Ad Hoc On-Demand Distance Vector (AODV) to obtain performance results using Network Simulator 2 simulation tool. The performance of the proposed approach has been compared with the traditional AODV implementation in terms of path duration.

Analogous to the way humans use the Internet, devices will be the main users in the Internet of Things (IoT) ecosystem. Therefore, device-to-device (D2D) communication is expected to be an intrinsic part of the IoT. Devices will communicate with each other autonomously without any centralized control and collaborate to gather, share, and forward information in a multihop manner. The ability to gather relevant information in real time is key to leveraging the value of the IoT as such information will be transformed into intelligence, which will facilitate the creation of an intelligent environment. Ultimately, the quality of the information gathered depends on how smart the devices are. In addition, these communicating devices will operate with different networking standards, may experience intermittent connectivity with each other, and many of them will be resource constrained. These characteristics open up several networking challenges that traditional routing protocols cannot solve. Consequently, devices will require intelligent routing protocols in order to achieve intelligent D2D communication. We present an overview of how intelligent D2D communication can be achieved in the IoT ecosystem. In particular, we focus on how state-of-the-art routing algorithms can achieve intelligent D2D communication in the IoT.