taglinefilesource code
ARC_P_IP1663drivers/net/arcnet.chead->protocol_id=ARC_P_IP;
ARC_P_IP1733drivers/net/arcnet.cif(head->protocol_id != ARC_P_IP) 
ARC_P_IP1785drivers/net/arcnet.ccase ARC_P_IP:    return htons(ETH_P_IP); /* what the heck is