Force refresh (re-scan) wireless networks from command line?
I've been looking for the same thing for a while now, unfortunately I can't seem to find anything in the netsh utility to do this. The best solution I was able to come up with was to disable then re-enable the interface through the netsh commands. There's a small delay (1-2 seconds) after enabling the interface where it won't list any networks, but that shouldn't be too hard to workaround.
I'm using the following commands:
netsh interface set interface name="<NIC name>" admin=disabled
netsh interface set interface name="<NIC name>" admin=enabled
netsh wlan show networks
Edit: How to get then the
"<NIC name>", i.e., the Network Interface Card name.
First of all use the command netsh wlan show networks
If the wlan is enabled you will get a message like this
C:\Users\user1>netsh wlan show networks
Interface name : WiFi
There are 2 networks currently visible.
SSID 1 : Cross
Network type : Infrastructure
Authentication : WPA2-Personal
Encryption : CCMP
SSID 2 : WLAN-0A8E41
Network type : Infrastructure
Authentication : WPA2-Personal
Encryption : CCMP
So you see, in this case, the interface name is WiFi
Now, you can proceed as explained above, for example to disable the wlan card:
netsh interface set interface name="WiFi" admin=disabled
And so on. :)
I wrote a small (~2 KiB) WlanScan.exe program to do this.
Here's the base64 (32-bit version):
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
You can save it to a file from PowerShell like this (save the Base64 to WlanScan.txt first):
Set-Content -Path "WlanScan.exe" $([Convert]::FromBase64String($(Get-Content -Path "WlanScan.txt"))) -Encoding Byte
Here's the source code:
#include <tchar.h>
#include <Windows.h>
#ifndef __CRT_STRINGIZE
#define __CRT_STRINGIZE(Value) #Value
#endif
#ifndef _CRT_STRINGIZE
#define _CRT_STRINGIZE(Value) __CRT_STRINGIZE(Value)
#endif
enum { WLAN_NOTIFICATION_SOURCE_ACM = 0x00000008 };
typedef enum _WLAN_NOTIFICATION_ACM { wlan_notification_acm_start, wlan_notification_acm_autoconf_enabled, wlan_notification_acm_autoconf_disabled, wlan_notification_acm_background_scan_enabled, wlan_notification_acm_background_scan_disabled, wlan_notification_acm_bss_type_change, wlan_notification_acm_power_setting_change, wlan_notification_acm_scan_complete, wlan_notification_acm_scan_fail, wlan_notification_acm_connection_start, wlan_notification_acm_connection_complete, wlan_notification_acm_connection_attempt_fail, wlan_notification_acm_filter_list_change, wlan_notification_acm_interface_arrival, wlan_notification_acm_interface_removal, wlan_notification_acm_profile_change, wlan_notification_acm_profile_name_change, wlan_notification_acm_profiles_exhausted, wlan_notification_acm_network_not_available, wlan_notification_acm_network_available, wlan_notification_acm_disconnecting, wlan_notification_acm_disconnected, wlan_notification_acm_adhoc_network_state_change, wlan_notification_acm_profile_unblocked, wlan_notification_acm_screen_power_change, wlan_notification_acm_profile_blocked, wlan_notification_acm_scan_list_refresh, wlan_notification_acm_end } WLAN_NOTIFICATION_ACM, *PWLAN_NOTIFICATION_ACM;
typedef enum _WLAN_INTERFACE_STATE { wlan_interface_state_not_ready, wlan_interface_state_connected, wlan_interface_state_ad_hoc_network_formed, wlan_interface_state_disconnecting, wlan_interface_state_disconnected, wlan_interface_state_associating, wlan_interface_state_discovering, wlan_interface_state_authenticating } WLAN_INTERFACE_STATE, *PWLAN_INTERFACE_STATE;
typedef struct _WLAN_INTERFACE_INFO { GUID InterfaceGuid; WCHAR strInterfaceDescription[256]; WLAN_INTERFACE_STATE isState; } WLAN_INTERFACE_INFO;
typedef struct _WLAN_INTERFACE_INFO_LIST { DWORD dwNumberOfItems; DWORD dwIndex; WLAN_INTERFACE_INFO InterfaceInfo[1]; } WLAN_INTERFACE_INFO_LIST;
typedef struct _WLAN_NOTIFICATION_DATA { DWORD NotificationSource; DWORD NotificationCode; GUID InterfaceGuid; DWORD dwDataSize; void *pData; } WLAN_NOTIFICATION_DATA, *PWLAN_NOTIFICATION_DATA;
typedef void WINAPI WLAN_NOTIFICATION_CALLBACK(WLAN_NOTIFICATION_DATA *, void *);
typedef struct wlan_scan_finished_context { WLAN_INTERFACE_INFO_LIST *interface_list; HANDLE semaphore; } wlan_scan_finished_context;
static void WINAPI wlan_notification_callback(WLAN_NOTIFICATION_DATA *data, void *context)
{
if ((data->NotificationSource | WLAN_NOTIFICATION_SOURCE_ACM) == WLAN_NOTIFICATION_SOURCE_ACM)
{
if (data->NotificationCode == wlan_notification_acm_power_setting_change || data->NotificationCode == wlan_notification_acm_scan_complete)
{
wlan_scan_finished_context *const ctx = (wlan_scan_finished_context *)context;
if (ctx)
{
for (unsigned int i = 0; i != (ctx->interface_list ? ctx->interface_list->dwNumberOfItems : 0); ++i)
{
if (memcmp(&ctx->interface_list->InterfaceInfo[i].InterfaceGuid, &data->InterfaceGuid, sizeof(data->InterfaceGuid)) == 0)
{
ctx->interface_list->InterfaceInfo[i].isState = (WLAN_INTERFACE_STATE)(ctx->interface_list->InterfaceInfo[i].isState | (data->NotificationCode << 16));
}
}
if (ctx->semaphore) { long prev; ReleaseSemaphore(ctx->semaphore, 1, &prev); }
}
}
}
}
int _tmain(int argc, TCHAR *argv[])
{
(void)argv;
unsigned int result;
if (argc > 1) { result = ERROR_INVALID_PARAMETER; }
else
{
HMODULE const wlanapi = LoadLibrary(TEXT("wlanapi.dll"));
if (wlanapi)
{
#define X(Module, Return, Name, Params) typedef Return Name##_t Params; Name##_t *Name = (Name##_t *)GetProcAddress(Module, __CRT_STRINGIZE(Name));
X(wlanapi, DWORD WINAPI, WlanCloseHandle, (HANDLE hClientHandle, void *pReserved));
X(wlanapi, DWORD WINAPI, WlanEnumInterfaces, (HANDLE hClientHandle, void *pReserved, struct _WLAN_INTERFACE_INFO_LIST **ppInterfaceList));
X(wlanapi, void WINAPI, WlanFreeMemory, (void *pMemory));
X(wlanapi, DWORD WINAPI, WlanOpenHandle, (DWORD dwClientVersion, void *pReserved, DWORD *pdwNegotiatedVersion, HANDLE *phClientHandle));
X(wlanapi, DWORD WINAPI, WlanRegisterNotification, (HANDLE hClientHandle, DWORD dwNotifSource, BOOL bIgnoreDuplicate, WLAN_NOTIFICATION_CALLBACK funcCallback, void *pCallbackContext, void *pReserved, DWORD *pdwPrevNotifSource));
X(wlanapi, DWORD WINAPI, WlanScan, (HANDLE hClientHandle, const GUID *pInterfaceGuid, const struct _DOT11_SSID *pDot11Ssid, const struct _WLAN_RAW_DATA *pIeData, void *pReserved));
#undef X
DWORD version;
HANDLE handle = NULL;
result = WlanOpenHandle ? WlanOpenHandle(1, NULL, &version, &handle) : ERROR_PROC_NOT_FOUND;
if (result == ERROR_SUCCESS)
{
WLAN_INTERFACE_INFO_LIST *interface_list = NULL;
result = WlanEnumInterfaces ? WlanEnumInterfaces(handle, NULL, &interface_list) : ERROR_PROC_NOT_FOUND;
if (result == ERROR_SUCCESS)
{
wlan_scan_finished_context context = { interface_list, CreateSemaphore(NULL, 0, (LONG)interface_list->dwNumberOfItems, NULL) };
DWORD prev;
unsigned int nwait = 0;
unsigned long const register_notification_result = WlanRegisterNotification ? WlanRegisterNotification(handle, WLAN_NOTIFICATION_SOURCE_ACM, FALSE, wlan_notification_callback, &context, NULL, &prev) : ERROR_PROC_NOT_FOUND;
for (unsigned int i = 0; i != interface_list->dwNumberOfItems; ++i)
{
unsigned int const result_i = WlanScan ? WlanScan(handle, &interface_list->InterfaceInfo[i].InterfaceGuid, NULL, NULL, NULL) : ERROR_PROC_NOT_FOUND;
interface_list->InterfaceInfo[i].isState = (WLAN_INTERFACE_STATE)(interface_list->InterfaceInfo[i].isState & 0xFFFF);
if (result_i == ERROR_SUCCESS) { ++nwait; }
else { interface_list->InterfaceInfo[i].isState = (WLAN_INTERFACE_STATE)(interface_list->InterfaceInfo[i].isState | (result_i << 16)); }
}
while (nwait > 0)
{
WaitForSingleObject(context.semaphore, INFINITE);
--nwait;
}
for (unsigned int i = 0; i != interface_list->dwNumberOfItems; ++i)
{
unsigned int const result_i = interface_list->InterfaceInfo[i].isState >> 16;
if (register_notification_result == ERROR_SUCCESS && result_i != ERROR_SUCCESS)
{ result = result_i; }
}
if (result == ERROR_SUCCESS && register_notification_result != ERROR_SUCCESS) { result = ERROR_IO_PENDING; }
if (context.semaphore) { CloseHandle(context.semaphore); }
WlanFreeMemory ? WlanFreeMemory(interface_list) : ERROR_PROC_NOT_FOUND;
}
WlanCloseHandle ? WlanCloseHandle(handle, NULL) : ERROR_PROC_NOT_FOUND;
}
}
else { result = (unsigned int)GetLastError(); }
}
return (int)result;
}
The networks are updated only when a scan is completed by your WiFi card. The NETSH command does not request a scan; it only displays the cached results of the last scan.
Opening the Windows network list from the taskbar updates the results because the taskbar network tool happens to request a scan when it's opened.
There is no
NETSHcommand to request a scan like this. You would have to write some code, leveraging either the Win32 WlanScan function (C# wrappers exist if you prefer that), or the WinRT ScanAsync function.
(Adapted/updated from the source.)
Related:
- Stack Overflow : How can I get the name of the current network in Excel VBA?
- Stack Overflow : Using WMI to Determine which adapter(s) is connected to the internet
- Microsoft Docs :
WiFiAdapterClass - Microsoft Docs :
WlanScanfunction