Abstract: With the emergence of unidirectional links and asymmetric applications requirements, traditional routing algorithms and protocols for bi\|directional and symmetric links are facing some severe challenges. Tunnel encapsulation and route modification are two common solutions to the short\|term scenario where some unidirectional links are added into the connected bi\|directional networks, but they also fail to meet the long\|term scenario where only unidirectional links are available. Following the definition of graph topology and network routing, a bounded neighbor discovery algorithm is proposed, and the upper bound on trips of any loop crossing one specified links is proved. A path generation algorithm based on the neighbor/path matrix is also presented and validated by some examples.