我正在尝试使用代码来检查网络上的计算机是否在线,该代码应该使用 ARP 数据包来检查它。
即使我确定它在线,我总是收到主机离线的消息。我检查了我的本地主机 IP 和一些始终工作的 IP,例如谷歌。
这段代码可能有问题吗?
[DllImport("iphlpapi.dll", ExactSpelling = true)]
public static extern int SendARP(IPAddress DestIP, int SrcIP, byte[] pMacAddr, ref uint PhyAddrLen);
private byte[] macAddr = new byte[6];
private uint macAddrLen;
private void Ping(IPAddress address)
{
if (SendARP(address, 0, new byte[6], ref macAddrLen) == 0)
{
open++;
txtDisplay.AppendText("Host " + address + " is open." + Environment.NewLine);
}
else
{
closed++;
txtDisplay.AppendText("Host " + address + " is closed." + Environment.NewLine);
}
}
通过使用以前的代码,我基本上是在尝试执行类似以下代码的操作。但是这段代码的问题是,当主机关闭时,需要大约 2 秒才能获得我想要消除的响应。有人建议使用 ARP ping:
private void Ping(IPAddress address)
{
Ping pingSender = new Ping();
PingOptions options = new PingOptions();
if (cbDontFragment.Checked) options.DontFragment = true;
else options.DontFragment = false;
string dataa = string.Empty;
int dataCounter = 0;
options.Ttl = (int)nudTTL.Value;
for (int i = 0; i < nudData.Value; i++)
{
dataCounter++;
if (dataCounter == 10) dataCounter = 0;
dataa += dataCounter.ToString();
}
byte[] buffer = Encoding.ASCII.GetBytes(dataa);
int timeout = 120;
try
{
PingReply reply = pingSender.Send(address, timeout, buffer, options);
if (reply.Status == IPStatus.Success)
{
open++;
txtDisplay.AppendText("Host " + address + " is open. ");
if (cbDontFragment.Checked) txtDisplay.AppendText(" Don't fragment. ");
txtDisplay.AppendText(" TTL: " + options.Ttl.ToString() + " ");
txtDisplay.AppendText(" Bytes: " + nudData.Value + " ");
txtDisplay.AppendText(Environment.NewLine);
}
else
{
closed++;
txtDisplay.AppendText("Host " + address + " is closed. ");
if (cbDontFragment.Checked) txtDisplay.AppendText(" Don't fragment. ");
txtDisplay.AppendText(" TTL: " + options.Ttl.ToString() + " ");
txtDisplay.AppendText(" Bytes: " + nudData.Value + " ");
txtDisplay.AppendText(Environment.NewLine);
}
}
catch (Exception ex)
{
txtDisplay.SelectedText += Environment.NewLine + ex.Message;
}
}