This paper introduces cross-layer implementation with a multi-rate aware routing scheme and shows that SNR is an important information to use in a routing protocol. The existing routing protocol attempts to minimize the number of hops between source-destination pairs. We use a new metric definition to route the packets and to select the best available link along the path in a multi-rate protocol senario. The new metric is created with information coming from inter-layer interaction between the routing layer and the MAC layer. We use SNR as an information about link quality. We show through simulation that for communications using muti-rate protocol in ad hoc networks, throughput is highly affected as soon as the route goes through low-rate link.