In this paper, we assess the protection mechanisms entered into recent clients to fight against the Sybil attack in KAD, a widely deployed Distributed Hash Table. We study three main mechanisms: a protection against flooding through packet tracking, an IP address limitation and a verification of identities. We evaluate their efficiency by designing and adapting an attack for several KAD clients with different levels of protection. Our results show that the new security rules mitigate the Sybil attacks previously launched. However, we prove that it is still possible to control a small part of the network despite the new inserted defenses with a distributed eclipse attack and limited resources.