Mobile IP has been proposed for a solution to provide IP-layer mobility including handoffs between subnets served by different Foreign Agents. However, the latency involved in these handoffs can be longer than the threshold value, required to support the delay-sensitive or real-time services. To reduce the latency for Mobile IPv4 handoffs, this paper presents a move detection mechanism within IP-layer. Proposed method is based on strict source routing in IP specification and includes the extension of router advertisement message and ICMP error reports. The proposed method is verified through the numerical results and the experimental results.