b->flags &= ~VNET_BUFFER_F_OFFLOAD_TCP_CKSUM;
b->flags &= ~VNET_BUFFER_F_OFFLOAD_UDP_CKSUM;
b->flags &= ~VNET_BUFFER_F_OFFLOAD_IP_CKSUM;
b->flags &= ~VNET_BUFFER_F_OFFLOAD_TCP_CKSUM;
b->flags &= ~VNET_BUFFER_F_OFFLOAD_UDP_CKSUM;
b->flags &= ~VNET_BUFFER_F_OFFLOAD_IP_CKSUM;