A method for maintaining packet's source network identification information while aggregating packets from a plurality of networks is provided. An ingress packet is processed to extract a plurality of packet header fields and port identifier. A first hash index is generated by hashing information associated with the plurality of packet header fields. The extracted port identifier is stored in a hash table using the generated first hash index. The ingress packet is forwarded to one or more inline tool devices. An egress packet received from the one or more inline tools is processed to extract the plurality of packet header fields. A second hash index is generated by hashing information associated with the plurality of packet header fields. The port identifier is retrieved from the hash table based on the generated second hash index. The egress packet is transmitted to a switching device based on the retrieved port identifier.