2025年VC++ 设置网卡接口MTU大小

科技前沿 • 2025-03-08 23:48 • 阅读 38

大家好，我是讯享网，很高兴认识大家。

在 Windows C/C++ 之中一共有三种方法可以设置网卡的MTU大小。

方法一：

SetIpInterfaceEntry 法

 static bool SetInterfaceMtu2(int interface_index, int mtu) noexcept { PIP_ADAPTER_ADDRESSES pAddresses = NULL; ULONG ulBufLen = 0; GetAdaptersAddresses(AF_UNSPEC, 0, NULL, pAddresses, &ulBufLen); char* szBuf = (char*)Malloc(ulBufLen); pAddresses = (IP_ADAPTER_ADDRESSES*)szBuf; if (NULL == pAddresses) { return false; } NETIOAPI_API dwErr = GetAdaptersAddresses(AF_INET, GAA_FLAG_SKIP_ANYCAST, NULL, pAddresses, &ulBufLen); if (dwErr == NO_ERROR) { while (NULL != pAddresses) { if (pAddresses->IfIndex == interface_index) { MIB_IPINTERFACE_ROW ifRow; InitializeIpInterfaceEntry(&ifRow); //interested name ifRow.InterfaceLuid = pAddresses->Luid; ifRow.Family = AF_INET; ifRow.NlMtu = mtu; dwErr = SetIpInterfaceEntry(&ifRow); break; } pAddresses = pAddresses->Next; } } Mfree(szBuf); return dwErr == NO_ERROR; }

讯享网

方法二：

SetIfEntry 法

讯享网 std::shared_ptr<MIB_IFROW> GetIfEntry(int interface_index) noexcept { if (interface_index < 0) { return NULL; } std::shared_ptr<MIB_IFROW> pIfRow = std::shared_ptr<MIB_IFROW>((MIB_IFROW*)Malloc(sizeof(MIB_IFROW)), [](MIB_IFROW* p) noexcept { Mfree(p); }); if (NULL == pIfRow) { return NULL; } pIfRow->dwIndex = interface_index; if (::GetIfEntry(pIfRow.get()) != NO_ERROR) { return NULL; } return pIfRow; } int GetInterfaceMtu(int interface_index) noexcept { std::shared_ptr<MIB_IFROW> ifRow = GetIfEntry(interface_index); if (NULL == ifRow) { return -1; } else { return ifRow->dwMtu; } } bool SetInterfaceMtu(int interface_index, int mtu) noexcept { // https://learn.microsoft.com/en-us/windows/win32/api/netioapi/nf-netioapi-getifentry2 // https://learn.microsoft.com/en-us/windows/win32/api/iphlpapi/nf-iphlpapi-getifentry std::shared_ptr<MIB_IFROW> ifRow = GetIfEntry(interface_index); if (NULL == ifRow) { return false; } if (ifRow->dwMtu == mtu) { return true; } else { ifRow->dwMtu = mtu; } DWORD dwErr = SetIfEntry(ifRow.get()); if (dwErr == NO_ERROR) { if (GetInterfaceMtu(interface_index) == mtu) { return true; } } return SetInterfaceMtu2(interface_index, mtu); }

方法三：

命令行法

讯享网

查看网络接口设置（MTU列项）

netsh interface ipv4 show subinterfaces

通过网络接口索引来管理，MTU是大小，10为网络接口索引

netsh interface ipv4 set subinterface 10 mtu=1400 store=persistent

通过网络接口名字来管理，MTU是大小，eth0为网络接口名

netsh interface ipv4 set subinterface eth0 mtu=1400 store=persistent

2025年VC++ 设置网卡接口MTU大小

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