udp query on localhost

Hello,
I have a couple of small powershell functions. One sends a ping and receives a response, the other sends a request for info and receives a response.

At first I had two separate functions to do the send/receive (create a udpclient do the send, close the udpclient. Then create another udpclient and do the receive).

But I found that sometimes when sending an info query to a server running on the localhost it would respond so quickly that the receive would miss the server info. I would only get some junk at the end of the response.

So now I create a udpclient do the send/receive then close udpclient. And this works just fine for a remoteip.

Most of the time on localhost the response comes so fast that the receive misses it. And just holds the port open forever.

Any idea how to get this to work consistently for a local or remote server? TIA

$localIP = '10.0.0.3'
$remoteIP = 'any remote server'
$script:ipAddr = $localIP
$scriptort = 27025

function hlinfo
{
$endpoint = new-object System.Net.IPEndPoint ([IPAddress]$ipAddr,$port)
$udpclient = new-Object System.Net.Sockets.udpclient
# 25 byte array.
$a = New-Object byte[] 25

# 255255255255TSource Engine Query0, from developer.valvesoftware wiki
$a = 0xff,0xff,0xff,0xff,0x54,0x53,0x6f,0x75,0x72,0x63,0x65,0x20,0x45,0x6e,0x67,0x69,0x6e,0x65,0x20,0x51,0x75,0x65,0x72,0x79,0x00

# send query
$bytesSent = $udpclient.Send($a,$a.length,$endpoint)

# save the sent from port number.
$script:lepp = $udpclient.client.localendpoint.port

$c = [Text.Encoding]::ASCII.GetString($a)
echo "`"$c`" Sent to: $endpoint From Local UDP Port: $lepp"

# receive response, the server info
echo "Listening for response on: $ipaddr`:$lepp"

# store response in a byte array.
$content = $udpclient.Receive([ref]$endpoint)

# make it a string and find the map name.
$c = [Text.Encoding]::ASCII.GetString($content)
$d = $c.split([char][byte]"0x20")
$e = $d[3] | select-string "svencoop4" | % { $_ -replace "svencoop4","" }
$f = $e.split("`]") | select-string "Sven" | % { $_ -replace "Sven","" }
echo "map$f"
$f | set-content c:\scripts\lastmap.txt
$udpclient.Close()
}

function hlping
{
$endpoint = new-object System.Net.IPEndPoint ([IPAddress]$ipAddr,$port)
$udpclient = new-Object System.Net.Sockets.udpclient

# 5 byte array.
$a = New-Object byte[] 5

# ff ff ff ff 69
$a = 0xff,0xff,0xff,0xff,0x69

# send ping
$bytesSent = $udpclient.Send($a,$a.length,$endpoint)

# save the sent from port number.
$script:lepp = $udpclient.client.localendpoint.port

$c = [Text.Encoding]::ASCII.GetString($a)
echo "`"$c`" Sent to: $endpoint From Local UDP Port: $lepp"

# ping reply
echo "Listening for response on: $ipaddr`:$lepp"
$content = $udpclient.Receive([ref]$endpoint)
$c = [Text.Encoding]::ASCII.GetString($content)
$d = $c.split("?")
if ($d -eq "j"){ echo alive } else { echo "server down" }
$udpclient.Close()
}

# main
hlping
hlinfo

solution: set local IP to 127.0.0.1

Works fine. Wonder why it did not work using my computers lan IP?