公网Server S能接受到某一公司内网主机E1发来的登陆消息，但是S返回的消息，E1无法接收。是否是公司网关拦截导致的？
代码如下。S端线输入SINIT,然后E1端运行E1Init，然后E1无法接受返回消息。
static void Main(string[] args)
{
string serveraddr = "116.233.234.159";
int port = 8600;
long e1Addr = 0, e2Addr = 0;
int e1Port = 0, e2Port = 0;
System.Net.Sockets.UdpClient u = new System.Net.Sockets.UdpClient(port);
while (true)
{
string cm = Console.ReadLine();
if (cm == "SINIT")
{
while (true)
{
System.Net.IPEndPoint ep = new System.Net.IPEndPoint(0, 0);
byte[] msg = u.Receive(ref ep);
if (Encoding.ASCII.GetString(msg) == "Hello1")
{
e1Addr = ep.Address.Address;
e1Port = ep.Port;
for(int i=0;i<1000;i++)
u.Send(Encoding.ASCII.GetBytes("OK"), 2, ep);
}
else if (Encoding.ASCII.GetString(msg) == "Hello2")
{
e2Addr = ep.Address.Address;
e2Port = ep.Port;
u.Send(Encoding.ASCII.GetBytes("OK"), 2, ep);
}
else if (Encoding.ASCII.GetString(msg) == "Need2")
{
byte[] t = new byte[sizeof(long) + sizeof(int)];
Array.Copy(BitConverter.GetBytes(e2Addr), t, sizeof(long));
Array.Copy(BitConverter.GetBytes(e2Port), 0, t, sizeof(long), sizeof(int));
u.Send(t, t.Length, ep);
}
Console.WriteLine(Encoding.ASCII.GetString(msg));
System.Threading.Thread.Sleep(100);
}
}
else if (cm == "E1Init")
{
System.Net.IPEndPoint ep = new System.Net.IPEndPoint(ConvertToIPValue(serveraddr), port);
u.Send(Encoding.ASCII.GetBytes("Hello1"), 6, ep);
byte[] msg = u.Receive(ref ep);
Console.WriteLine(Encoding.ASCII.GetString(msg));
}
else if (cm == "Need2")
{
System.Net.IPEndPoint ep = new System.Net.IPEndPoint(ConvertToIPValue(serveraddr), port);
u.Send(Encoding.ASCII.GetBytes("Need2"), 6, ep);
byte[] msg = u.Receive(ref ep);
long addr = BitConverter.ToInt64(msg, 0);
int e2p = BitConverter.ToInt32(msg, sizeof(long));
Console.WriteLine(addr + " " + e2p);
ep = new System.Net.IPEndPoint(addr, e2p);
u.Send(Encoding.ASCII.GetBytes("Hellop from e1"), "Hellop from e1".Length, ep);
}