Obtaining traffic load on internal links of the network is crucial for network management and control. Though collecting can be available on each link, such as applying traditional SNMP scheme, the approach would be expensive because it may cause heavy processing load and sharply degrade the throughput of the core routers in high-speed IP backbone. Then monitoring merely at the edge and estimating traffic in the core provides a good alternative way for overcoming such functionality limitations. In this paper, we explore a scheme on deriving internal link load of network with edge-based measurements. Contrast to collecting routing data from core routers that costs much, we propose a route probing method based on hash sampling techniques and IP Measurement protocol between node-pairs. Based on statistical theory, we prove that our approach is effective and present the algorithm. Performance simulation results show the potential of our approach.