Some Notes on the Machines

So we have the situation where we have multiple network interfaces, possibly including wireless, and we want to set priority, so if one is connected, that one will be used. Here’s a good working procedure, all in Powershell.

1. Get list of interfaces with the Windows index number for each:

Get-NetIPInterface | ft ifINdex,InterfaceAlias,AddressFamily

Now we have a list of interfaces and names. Each interface device may have two listings, one for IPv6 and one for IPv4. What we want is the index numbers for the two. On one machine, “Ethernet” was index 12, and “Wifi” was 18, but there will be wide variation.

2. Priority is higher, for lower numbers. So if we want to set high priority for wired Ethernet when it’s present, we could set priority 10:

Set-NetIPInterface -InterfaceIndex "12" -InterfaceMetric "10"

3. and to make it stick and work predictably, we set Wifi to priority 100:

Set-NetIPInterface -InterfaceIndex "18" -InterfaceMetric "100"

One can do a basic test of TCP using Putty. UDP is another matter, one must have a server process and a sender. I found the simple sender and server written in Powershell here:

cloudbrothers.info/en/test-udp-connection-powershell/

to be excellent. In addition, if you want to know the identity of the process listening on a port, run this:

Get-Process -Id (Get-NetUDPEndpoint -LocalPort YourPortNumberHere).OwningProcess

100 Kbps is more than enough.

A great summary of FTP conversation over TCP:

https://www.ncftp.com/libncftp/doc/ftp_overview.html

https://github.com/billziss-gh/sshfs-win

CLI command:

net use X: \\sshfs\login@hostname.fqdn

Here is a tool for this purpose:

https://iperf.fr/iperf-download.php

Here they are:

https://support.eset.com/kb332/

To set a Windows NIC to full DHCP via netsh, do this, replacing “Local Area Connection” to the name of the NIC if it’s not the same:

netsh interface ip set address "Local Area Connection" dhcp
netsh interface ip set dns "Local Area Connection" dhcp
netsh interface ip set wins "Local Area Connection" dhcp

Sometimes, if WINS is set static, you have to do this before WINS can be set DHCP:

netsh interface ip set wins "Local Area Connection" static none

To learn what is going on NetBIOS-wise on your LAN, in Windows, do this:

NBTSTAT -r

This will get you something like the below. If you have WINS active — which is essential for NetBIOS and group policy over a VPN if you don’t do IPv6 — you will see the names resolved by name server as below. If not, if names are resolved by broadcast, you don’t have WINS, and NetBIOS will not work across VPN.

    NetBIOS Names Resolution and Registration Statistics
    ----------------------------------------------------

    Resolved By Broadcast     = 0
    Resolved By Name Server   = 1187

    Registered By Broadcast   = 0
    Registered By Name Server = 6

Excellent tool:

http://www.advanced-ip-scanner.com/