服务端怎么获取真实的客户端ip地址

获取客户端真实IP地址需要考虑到代理、负载均衡等因素。一般情况下，可以通过读取HTTP请求头中的X-Forwarded-For字段来获取客户端真实IP地址。如果该字段不存在，则可以尝试读取RemoteAddr字段。如果你使用的是Java语言，可以使用以下代码获取客户端真实IP地址：

HttpServletRequest request = ...;
String ip = request.getHeader("X-Forwarded-For");
if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
    ip = request.getHeader("Proxy-Client-IP");
}
if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
    ip = request.getHeader("WL-Proxy-Client-IP");
}
if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
    ip = request.getHeader("HTTP_CLIENT_IP");
}
if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
    ip = request.getHeader("HTTP_X_FORWARDED_FOR");
}
if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
    ip = request.getRemoteAddr();
}

以上代码会依次尝试读取X-Forwarded-For、Proxy-Client-IP、WL-Proxy-Client-IP、HTTP_CLIENT_IP、HTTP_X_FORWARDED_FOR和RemoteAddr字段，如果这些字段中有一个包含客户端真实IP地址，则返回该地址；否则，返回null。