In IP networks, packets are freely transferred across the global network without regulatory oversight, often facilitating cyber-attacks and criminal activities. Multi-Identifier Network introduces a groundbreaking network architecture that utilizes blockchain technology to manage multiple independent network domains through a collaborative consensus mechanism. This paper introduces a new border management protocol within the network layer of Multi-Identifier Network, effectively enhancing control over cyberspace borders. This innovative protocol allows for separate governance of different domains, with the possibility to regulate and monitor data flow between these domains. It requires that a user and their domain’s border router sign two hash values on outgoing packets. The receiving domain’s border router subsequently uses these hash values to determine the admissibility of incoming packets. We present the architecture of the border router, and a lightweight extension to detect cross-domain Interest Flooding Attacks. Experimental results demonstrate that our protocol effectively manages cyberspace borders and detects cross-domain attacks, significantly enhancing security and regulatory measures within the network layer.