Question

外网如何获取内网的IP？

如果用户在局域网内使用内部IP进行外网服务器访问，如何在服务器端获得用户的局域网IP呢？
最好使用C#来实现，谢谢
能获取客户端计算机名也行，可以吗？

Answer 1

　　内网IP只能在内网局域网访问连接,在外网是不能认识内网IP不能访问的。有路由权限,且路由有固定公网IP,可以通过路由的端口映射,实现外网访问内网。如无路由,或路由无公网IP,需要借助第三方开放的nat123端口映射网络辅助实现外网访问内网。

　　端口映射网络辅助的好处是适用于任何网络环境,外网访问内网的实现过程:

　　1.在内网安装并启用nat123端口映射。添加映射,配置内外网映射信息,对应内网IP端口和外网自己的域名。外网地址可直接使用提示默认域名。

　　

　　2.NAT映射后,通过域名访问,即可以连接内网对应IP应用。

Answer 2

最近看到一些对IP的操作,感觉不错,而且以后可能会用到,所以收集过来,以备以后使用.

1.获取MAC地址操作:

using System;
using System.Runtime.InteropServices;

namespace UtilityControl
{
/// <summary>
/// 关于IP地址的若干操作
/// </summary>
public class IP
{
public IP()
{
//
// TODO: 在此处添加构造函数逻辑
//
}

[DllImport("Iphlpapi.dll")]
private static extern int SendARP(Int32 dest,Int32 host,ref Int64 mac,ref Int32 length);
[DllImport("Ws2_32.dll")]
private static extern Int32 inet_addr(string ip);

/// <summary>
/// 根据ip得到网卡mac地址
/// </summary>
/// <param name="ip">给出的ip地址</param>
/// <returns>对应ip的网卡mac地址</returns>
public static Int64 GetMACByIP(string ip)
{
Int32 ldest= inet_addr(ip); //目的地的ip
try
{
Int64 macinfo = new Int64();
Int32 len = 6;
int res = SendARP(ldest,0, ref macinfo, ref len);
return macinfo;
}
catch(Exception err)
{
Console.WriteLine("Error:{0}",err.Message);
}
return 0;
}
}
}

-----------------------------------------------------------------

用C#编写获取远程IP,MAC的方法

[DllImport("Iphlpapi.dll")]
private static unsafe extern int SendARP(Int32 dest,Int32 host,ref IntPtr mac,ref IntPtr length);
[DllImport("Ws2_32.dll")]
private static extern Int32 inet_addr(string ip);

Int32 ldest= inet_addr("157.60.68.163");//目的地的ip
Int32 lhost= inet_addr("157.60.68.33");//本地的ip

try
{
Byte[] macinfo=new Byte[6];
Int32 length=6;

IntPtr mac=new IntPtr(macinfo[0]);
IntPtr len=new IntPtr(6);
int ii=SendARP(ldest,lhost, ref mac, ref len);

Console.WriteLine("Mac Add:"+mac);
Console.WriteLine("length:"+len);

}
catch(Exception err)
{
Console.WriteLine(err);
}

-----------------------------------------------

用WMI
使用时首先添加System.Management.dll，然后引用
using System.Management;
using System.Threading;
{
ManagementClass mc = new ManagementClass("Win32_NetworkAdapterConfiguration");
ManagementObjectCollection moc = mc.GetInstances();
foreach(ManagementObject mo in moc)
{
if((bool)mo["IPEnabled"] == true)
Response.Write("MAC address"+mo["MacAddress"].ToString()+"<br/>");
mo.Dispose();
}
}

2.手动设置IP或设置动态IP

如果是winform的话，需要添加对System.Management.dll的引用

然后使用下面的类就可以实现你的前2个要求：
namespace modify
{
public class ChangeIP
{

public static readonly System.Version myVersion = new System.Version(1, 1);
private ManagementBaseObject iObj = null;
private ManagementBaseObject oObj = null;
private ManagementClass mc = new ManagementClass("Win32_NetworkAdapterConfiguration");
private readonly ManagementObjectCollection moc;

/// <summary>
/// example:
/// <code>
/// ArLi.CommonPrj.ChangeIP o = new ArLi.CommonPrj.ChangeIP();
/// string[] ipList = new string[]{"192.168.0.253","192.168.0.250"};
/// string[] subnetList = new string[]{"255.255.255.0","255.255.255.0"};
/// o.ChangeTo(ipList,subnetList);
/// </code>
/// </summary>
public ChangeIP()
{
moc = mc.GetInstances();
}

/// <summary>cortrol</summary>
/// <param name="ipAddr">IPAddr List</param>
/// <param name="subnetMask">subnetMask List</param>
public void ChangeTo(string[] ipAddr, string[] subnetMask)
{
foreach (ManagementObject mo in moc)
{
if (!(bool)mo["IPEnabled"]) continue;

iObj = mo.GetMethodParameters("EnableStatic");
iObj["IPAddress"] = ipAddr;
iObj["SubnetMask"] = subnetMask;
oObj = mo.InvokeMethod("EnableStatic", iObj, null);
}
}

/// <summary>cortrol</summary>
/// <param name="ipAddr">IPAddr List</param>
/// <param name="subnetMask">subnetMask List</param>
/// <param name="gateways">gateway List</param>
/// <param name="gatewayCostMetric">gateway CostMetric List, example: 1</param>
public void ChangeTo(string[] ipAddr, string[] subnetMask, string[] gateways, string[] gatewayCostMetric)
{
foreach (ManagementObject mo in moc)
{
if (!(bool)mo["IPEnabled"]) continue;

iObj = mo.GetMethodParameters("EnableStatic");
iObj["IPAddress"] = ipAddr;
iObj["SubnetMask"] = subnetMask;
oObj = mo.InvokeMethod("EnableStatic", iObj, null);

iObj = mo.GetMethodParameters("SetGateways");
iObj["DefaultIPGateway"] = gateways;
iObj["GatewayCostMetric"] = gatewayCostMetric;
oObj = mo.InvokeMethod("SetGateways", iObj, null);
}
}

/// <summary>cortrol</summary>
/// <param name="ipAddr">IPAddr List</param>
/// <param name="subnetMask">subnetMask List</param>
/// <param name="gateways">gateway List</param>
/// <param name="gatewayCostMetric">gateway CostMetric List, example: 1</param>
/// <param name="dnsServer">DNSServer List</param>
public void ChangeTo(string[] ipAddr, string[] subnetMask, string[] gateways, string[] gatewayCostMetric, string[] dnsServer)
{
foreach (ManagementObject mo in moc)
{
if (!(bool)mo["IPEnabled"]) continue;

iObj = mo.GetMethodParameters("EnableStatic");
iObj["IPAddress"] = ipAddr;
iObj["SubnetMask"] = subnetMask;
oObj = mo.InvokeMethod("EnableStatic", iObj, null);

iObj = mo.GetMethodParameters("SetGateways");
iObj["DefaultIPGateway"] = gateways;
iObj["GatewayCostMetric"] = gatewayCostMetric;
oObj = mo.InvokeMethod("SetGateways", iObj, null);

iObj = mo.GetMethodParameters("SetDNSServerSearchOrder");
iObj["DNSServerSearchOrder"] = dnsServer;
oObj = mo.InvokeMethod("SetDNSServerSearchOrder", iObj, null);
}
}

/// <summary>DHCPEnabled</summary>
public void EnableDHCP()
{
foreach (ManagementObject mo in moc)
{
if (!(bool)mo["IPEnabled"]) continue;

if (!(bool)mo["DHCPEnabled"])
{
iObj = mo.GetMethodParameters("EnableDHCP");
oObj = mo.InvokeMethod("EnableDHCP", iObj, null);
}
}
}
}
}

测试代码：
using System.Management;
using modify;
namespace WindowsApplication13
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
//对第二个问题验证
ChangeIP test = new ChangeIP();
string[] str1 = new string[] {"192.168.1.5"};
string[] str2 = new string[] { "255.255.255.0" };
test.ChangeTo(str1, str2);

MessageBox.Show("IP已经更改，请验证");

//对第一个问题的验证，如果IP可用，当前并不是自动获取IP，这时下面的方法会自动获取IP
test.EnableDHCP();
}
}
}

Answer 3

需要把内网的ip设置，放到公网上，外网自然就获取到了内网ip。

Answer 4

内网SVN应用使用场景时，使用nat123内网穿透客户端登录并添加443https应用类型映射方式。

对于办公OA、ERP等不收录的WEB网站，使用非80网站应用类型映射方式以实现外网的访问。

外网访问内网服务器时，如外网远程桌面和SSH内网LINUX机，都可以使用非网站应用类型映射方式实现外网的访问。

Answer 5

不能