Managing Access Control in Virtual Private Networks

Virtual Private Network technology allows remote network users to benefit from resources on a private network as if their host machines actually resided on the network. However, each resource on a network may also have its own access control policies, which may be completely unrelated to network access. Thus users� access to a network (even by VPN technology) does not guarantee their access to the sought resources. With the introduction of more complicated access privileges, such as delegated access, it is conceivable for a scenario to arise where a user can access a network remotely (because of direct permissions from the network administrator or by delegated permission) but cannot access any resources on the network. There is, therefore, a need for a network access control mechanism that understands the privileges of each remote network user on one hand, and the access control policies of various network resources on the other hand, and so can aid a remote user in accessing these resources based on the user\u27s privileges. This research presents a software solution in the form of a centralized access control framework called an Access Control Service (ACS), that can grant remote users network presence and simultaneously aid them in accessing various network resources with varying access control policies. At the same time, the ACS provides a centralized framework for administrators to manage access to their resources. The ACS achieves these objectives using VPN technology, network address translation and by proxying various authentication protocols on behalf of remote users

IPv6: a new security challenge

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

Utilization of RADIUS Protocol AV Pairs for Dynamic Configuration of Remote Access into Virtual Private Networks

Import 04/07/2011V této diplomové práci se zabývám návrhem a realizací dynamické konfigurace mechanizmů vzdáleného přístupu do virtuálních privátních sítí, založených na technologii MPLS/VPN. Pro přistup, jsou využívány technologie ISDN, PSTN, DSL, které jsou podpořeny protokolem RADIUS k umožnění dynamického předá\-vání konfigurace síťovým prvkům. V konfiguraci, jež je takto předávána, je sdělená nutnost budování síťových tunelů, které zapouzdřují daný provoz klientů, a umožňuje logické oddělení datových toků. Tyto tunely jsou zakončovány virtuálním přístupovým rozhraním umožňující předá\-vání toku dat do příslušných VRF daných zákazníků.In this diploma thesis I deal with design and realization of a dynamic configuration mechanism of remote access to virtual private networks, based on MPLS/VPN technology. For access, ISDN, PSTN, DLS technologies are used. These technologies are supported by protocol RADIUS which enables dynamic configuration transfer to network elements. In the configuration, which is so transferred exist necessity for building a network of tunnels that encapsulate the client operations, and allows logical separation of dataflows. These tunnels are terminated by virtual access interface which allows transmission of dataflow to the customer’s VRF.460 - Katedra informatikyvelmi dobř

Secure Configuration and Management of Linux Systems using a Network Service Orchestrator.

Manual management of the configuration of network devices and computing devices (hosts) is an error-prone task. Centralized automation of these tasks can lower the costs of management, but can also introduce unknown or unanticipated security risks. Misconfiguration (deliberate (by outsiders) or inadvertent (by insiders)) can expose a system to significant risks. Centralized network management has seen significant progress in recent years, resulting in model-driven approaches that are clearly superior to previous "craft" methods. Host management has seen less development. The tools available have developed in separate task-specific ways. This thesis explores two aspects of the configuration management problem for hosts: (1) implementing host management using the model-driven (network) management tools; (2) establishing the relative security of traditional methods and the above proposal for model driven host management. It is shown that the model-driven approach is feasible, and the security of the model driven approach is significantly higher than that of existing approaches