A method for performing LRO aggregation on packets being forwarded by a VM is provided. The method segments the LRO aggregated packet according to the Maximum Segment Size (MSS) of the TCP protocol before forwarding the segmented packets to their destination. The method snoops the packets being forwarded for its MSS parameter before using the snooped MSS parameter to perform Transmit Segmentation Offload (TSO) operation. The PNIC performs both the aggregation operation (LRO) and the segmentation (TSO) within its own hardware without consuming CPU cycles at the host machine. The PNIC receives the MSS parameter from the network stack as a metadata that accompanies a LRO aggregated packet.