438 research outputs found

    A practical approach to network-based processing

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    The usage of general-purpose processors externally attached to routers to play virtually the role of active coprocessors seems a safe and cost-effective approach to add active network capabilities to existing routers. This paper reviews this router-assistant way of making active nodes, addresses the benefits and limitations of this technique, and describes a new platform based on it using an enhanced commercial router. The features new to this type of architecture are transparency, IPv4 and IPv6 support, and full control over layer 3 and above. A practical experience with two applications for path characterization and a transport gateway managing multi-QoS is described.Most of this work has been funded by the IST project GCAP (Global Communication Architecture and Protocols for new QoS services over IPv6 networks) IST-1999-10 504. Further development and application to practical scenarios is being supported by IST project Opium (Open Platform for Integration of UMTS Middleware) IST-2001-36063 and the Spanish MCYT under projects TEL99-0988-C02-01 and AURAS TIC2001-1650-C02-01.Publicad

    IPv6: a new security challenge

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    Tese de mestrado em Segurança Informática, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2011O Protocolo de Internet versão 6 (IPv6) foi desenvolvido com o intuito de resolver alguns dos problemas não endereçados pelo seu antecessor, o Protocolo de Internet versão 4 (IPv4), nomeadamente questões relacionadas com segurança e com o espaço de endereçamento disponível. São muitos os que na última década têm desenvolvido estudos sobre os investimentos necessários à sua adoção e sobre qual o momento certo para que o mesmo seja adotado por todos os players no mercado. Recentemente, o problema da extinção de endereçamentos públicos a ser disponibilizado pelas diversas Region Internet registry – RIRs - despertou o conjunto de entidades envolvidas para que se agilizasse o processo de migração do IPv4 para o IPv6. Ao contrário do IPv4, esta nova versão considera a segurança como um objetivo fundamental na sua implementação, nesse sentido é recomendado o uso do protocolo IPsec ao nível da camada de rede. No entanto, e devido à imaturidade do protocolo e à complexidade que este período de transição comporta, existem inúmeras implicações de segurança que devem ser consideradas neste período de migração. O objetivo principal deste trabalho é definir um conjunto de boas práticas no âmbito da segurança na implementação do IPv6 que possa ser utilizado pelos administradores de redes de dados e pelas equipas de segurança dos diversos players no mercado. Nesta fase de transição, é de todo útil e conveniente contribuir de forma eficiente na interpretação dos pontos fortes deste novo protocolo assim como nas vulnerabilidades a ele associadas.IPv6 was developed to address the exhaustion of IPv4 addresses, but has not yet seen global deployment. Recent trends are now finally changing this picture and IPv6 is expected to take off soon. Contrary to the original, this new version of the Internet Protocol has security as a design goal, for example with its mandatory support for network layer security. However, due to the immaturity of the protocol and the complexity of the transition period, there are several security implications that have to be considered when deploying IPv6. In this project, our goal is to define a set of best practices for IPv6 Security that could be used by IT staff and network administrators within an Internet Service Provider. To this end, an assessment of some of the available security techniques for IPv6 will be made by means of a set of laboratory experiments using real equipment from an Internet Service Provider in Portugal. As the transition for IPv6 seems inevitable this work can help ISPs in understanding the threats that exist in IPv6 networks and some of the prophylactic measures available, by offering recommendations to protect internal as well as customers’ networks

    Secure Network Access via LDAP

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    Networks need the ability to be access by secure accounts and users. The goal of this project is to configure and expand on LDAP configurations with considerations for AAA via TACACS+ and Radius for network equipment. This will provide adequate security for any given network in terms of access and prevent lose of access to devices which happens all to often with locally configured accounts on devices

    Data Communications and Network Technologies

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    This open access book is written according to the examination outline for Huawei HCIA-Routing Switching V2.5 certification, aiming to help readers master the basics of network communications and use Huawei network devices to set up enterprise LANs and WANs, wired networks, and wireless networks, ensure network security for enterprises, and grasp cutting-edge computer network technologies. The content of this book includes: network communication fundamentals, TCP/IP protocol, Huawei VRP operating system, IP addresses and subnetting, static and dynamic routing, Ethernet networking technology, ACL and AAA, network address translation, DHCP server, WLAN, IPv6, WAN PPP and PPPoE protocol, typical networking architecture and design cases of campus networks, SNMP protocol used by network management, operation and maintenance, network time protocol NTP, SND and NFV, programming, and automation. As the world’s leading provider of ICT (information and communication technology) infrastructure and smart terminals, Huawei’s products range from digital data communication, cyber security, wireless technology, data storage, cloud-computing, and smart computing to artificial intelligence

    Coherent, automatic address resolution for vehicular ad hoc networks

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    Published in: Int. J. of Ad Hoc and Ubiquitous Computing, 2017 Vol.25, No.3, pp.163 - 179. DOI: 10.1504/IJAHUC.2017.10001935The interest in vehicular communications has increased notably. In this paper, the use of the address resolution (AR) procedures is studied for vehicular ad hoc networks (VANETs). We analyse the poor performance of AR transactions in such networks and we present a new proposal called coherent, automatic address resolution (CAAR). Our approach inhibits the use of AR transactions and instead increases the usefulness of routing signalling to automatically match the IP and MAC addresses. Through extensive simulations in realistic VANET scenarios using the Estinet simulator, we compare our proposal CAAR to classical AR and to another of our proposals that enhances AR for mobile wireless networks, called AR+. In addition, we present a performance evaluation of the behaviour of CAAR, AR and AR+ with unicast traffic of a reporting service for VANETs. Results show that CAAR outperforms the other two solutions in terms of packet losses and furthermore, it does not introduce additional overhead.Postprint (published version

    Multicast in a virtual privat network: the internet providers view

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    In the last decade we have witnessed a dramatic increase in bandwidth, which led to expand of services and allow providers to begin to offer other services such as video-based contents or IPTV, which operates on multicast technology. Almost everybody know packet offers of Internet providers, such as the so-called TRIO packets (Internet, telephony, and television). These services are usually offered to majority of users, called a private or residential customers. The majority of earnings of the ISPs bring business customers, which have significantly higher requirements than residential customers. Big business systems coordinate their dispersed locations together, through a network of Internet service provider. For example, a large trading company based in Ljubljana have in almost every major place of their own offices, and those offices communicate with the central place of business, through virtual private network (VPN below). This VPN is running through ISP network on the provider's edge (PE) routers, which communicate with the customer's edge (CE) routers. Service provider provides connectivity as well as routing which is running by routing protocol such as MPLS and BGP. From the user's perspective, VPN is visible as a large local area network(LAN). On the Cisco platform this allows implementation of VRF, which represents the routing and forwarding table of a specific VPN. The customers desire and demand is that the provider should provide all necessary conditions and technologies for running their business. One of these technologies is multicast, which client wishes to send within locations in its VPN. For example, the need for video conferencing or to transfer data of critical business applications. All bigger stock exchanges run multicast through their VPNs. This service is called multicast VPN or mVPN. To allow for this type of service transfer, provider must make some changes on their PE routers, and add some parameters within a VRF. MVPN service is like any other VPN services, running through providers network, the routing and management is taking care by the provider. We will get to know why the implementation of mVPN on service provider network is adequate if we want to offer multicast VPN to the enterprises, which would run their multicast VPN over service provider backbone

    Rationale, Scenarios, and Profiles for the Application of the Internet Protocol Suite (IPS) in Space Operations

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    This greenbook captures some of the current, planned and possible future uses of the Internet Protocol (IP) as part of Space Operations. It attempts to describe how the Internet Protocol is used in specific scenarios. Of primary focus is low-earth-orbit space operations, which is referred to here as the design reference mission (DRM). This is because most of the program experience drawn upon derives from this type of mission. Application profiles are provided. This includes parameter settings programs have proposed for sending IP datagrams over CCSDS links, the minimal subsets and features of the IP protocol suite and applications expected for interoperability between projects, and the configuration, operations and maintenance of these IP functions. Of special interest is capturing the lessons learned from the Constellation Program in this area, since that program included a fairly ambitious use of the Internet Protocol

    Data Communications and Network Technologies

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    This open access book is written according to the examination outline for Huawei HCIA-Routing Switching V2.5 certification, aiming to help readers master the basics of network communications and use Huawei network devices to set up enterprise LANs and WANs, wired networks, and wireless networks, ensure network security for enterprises, and grasp cutting-edge computer network technologies. The content of this book includes: network communication fundamentals, TCP/IP protocol, Huawei VRP operating system, IP addresses and subnetting, static and dynamic routing, Ethernet networking technology, ACL and AAA, network address translation, DHCP server, WLAN, IPv6, WAN PPP and PPPoE protocol, typical networking architecture and design cases of campus networks, SNMP protocol used by network management, operation and maintenance, network time protocol NTP, SND and NFV, programming, and automation. As the world’s leading provider of ICT (information and communication technology) infrastructure and smart terminals, Huawei’s products range from digital data communication, cyber security, wireless technology, data storage, cloud-computing, and smart computing to artificial intelligence

    Modelling PIM-SM in OMNeT++

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    Ve své diplomové práci se zabývám modelováním a simulací multicastového směrovacího protokolu PIM Sparse Mode v nástroji OMNeT++. Čtenář se seznámí se základními informacemi o multicastu, s protokolem PIM-SM, jeho konfigurací na zařízeních Cisco. Zároveň bude uveden do problematiky vizualizace multicastových toků v síti. Práce je zaměřena zejména na návrh a implementaci protokolu PIM-SM v OMNeT++ a rozšíření knihovny ANSAINET o další multicastový směrovací protokol.In this master's thesis I deal with modelling and simulating of multicast routing protocol PIM Sparse Mode in OMNeT++. I also describe basic information about multicast, protocol PIM-SM, its configuration and multicast data streams visualization in computer networks. The thesis is especially focused on design and implementation of PIM-SM in OMNeT++ and extension of ANSAINET library.
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