我想向用户显示当前的网络接口 mtu 值。用户可以通过 netsh 命令更改 mtu，例如 id 为 11 的接口：
netsh interface ipv4 set subinterface 11 mtu=1700 store=persistent
如何通过 id 或接口名称读取接口的当前 MTU？
如果我使用命名空间中的NetworkInterface类示例，System.Net.NetworkInformation所有接口的 MTU 为 1500。但使用 netsh 命令（见上文）我得到正确的 MTU 值，例如 1700。
这是一个例子：
public static void ShowNetworkInterfaces()
{
IPGlobalProperties computerProperties = IPGlobalProperties.GetIPGlobalProperties();
NetworkInterface[] nics = NetworkInterface.GetAllNetworkInterfaces();
Console.WriteLine("Interface information for {0}.{1} ",
computerProperties.HostName, computerProperties.DomainName);
if (nics == null || nics.Length < 1)
{
Console.WriteLine(" No network interfaces found.");
return;
}
Console.WriteLine(" Number of interfaces .................... : {0}", nics.Length);
foreach (NetworkInterface adapter in nics)
{
IPInterfaceProperties properties = adapter.GetIPProperties();
Console.WriteLine();
Console.WriteLine(adapter.Description);
Console.WriteLine(String.Empty.PadLeft(adapter.Description.Length,'='));
Console.WriteLine(" Interface type .......................... : {0}", adapter.NetworkInterfaceType);
Console.WriteLine(" Physical Address ........................ : {0}",
adapter.GetPhysicalAddress().ToString());
Console.WriteLine(" Operational status ...................... : {0}",
adapter.OperationalStatus);
string versions ="";
// Create a display string for the supported IP versions.
if (adapter.Supports(NetworkInterfaceComponent.IPv4))
{
versions = "IPv4";
}
if (adapter.Supports(NetworkInterfaceComponent.IPv6))
{
if (versions.Length > 0)
{
versions += " ";
}
versions += "IPv6";
}
Console.WriteLine(" IP version .............................. : {0}", versions);
ShowIPAddresses(properties);
// The following information is not useful for loopback adapters.
if (adapter.NetworkInterfaceType == NetworkInterfaceType.Loopback)
{
continue;
}
Console.WriteLine(" DNS suffix .............................. : {0}",
properties.DnsSuffix);
string label;
if (adapter.Supports(NetworkInterfaceComponent.IPv4))
{
IPv4InterfaceProperties ipv4 = properties.GetIPv4Properties();
Console.WriteLine(" MTU...................................... : {0}", ipv4.Mtu);
if (ipv4.UsesWins)
{
IPAddressCollection winsServers = properties.WinsServersAddresses;
if (winsServers.Count > 0)
{
label = " WINS Servers ............................ :";
ShowIPAddresses(label, winsServers);
}
}
}
Console.WriteLine(" DNS enabled ............................. : {0}",
properties.IsDnsEnabled);
Console.WriteLine(" Dynamically configured DNS .............. : {0}",
properties.IsDynamicDnsEnabled);
Console.WriteLine(" Receive Only ............................ : {0}",
adapter.IsReceiveOnly);
Console.WriteLine(" Multicast ............................... : {0}",
adapter.SupportsMulticast);
ShowInterfaceStatistics(adapter);
Console.WriteLine();
}