RDP: Access, Port, Multi-User and Issues

Complete guide to Remote Desktop on Windows Server - connection, port change, multiple simultaneous users and troubleshooting

Connect via RDP

From Windows

Open Remote Desktop Connection (mstsc or search "Remote desktop" in Start menu)
Enter server IP in Computer field
Click Connect
Enter username (Administrator) and password

For custom port (es. 3390):

185.100.xxx.xxx:3390

From Mac

Download Microsoft Remote Desktop from App Store (free):

Add PC → enter IP:port
Add user account
Double click to connect

From Linux

# With remmina (GUI)
sudo apt install remmina remmina-plugin-rdp -y
remmina

# With xfreerdp (terminal)
xfreerdp /v:185.100.xxx.xxx:3389 /u:Administrator /p:password /dynamic-resolution

Change RDP Port (from 3389)

Changing the port reduces automatic brute force attempts.

Open the new port in firewall before changing port in registry. Otherwise you'll lock yourself out.

Step 1: Open new port in firewall

# Replace 3390 with desired port
$NewPort = 3390

New-NetFirewallRule -DisplayName "RDP Custom Port" `
  -Direction Inbound -Protocol TCP -LocalPort $NewPort `
  -Action Allow -Profile Any

Step 2: Change port in registry

$NewPort = 3390

Set-ItemProperty -Path "HKLM:\SYSTEM\CurrentControlSet\Control\Terminal Server\WinStations\RDP-Tcp" `
  -Name "PortNumber" -Value $NewPort -Type DWord

# Restart RDP service
Restart-Service -Name "TermService" -Force

Step 3: Verify

# Check new port is listening
netstat -ano | findstr ":3390"

Now connect specifying IP:3390 in RDP client.

Enable Multiple RDP Sessions Simultaneously

Windows Server allows multiple RDP connections, but they're limited by default. To enable multiple sessions:

Via Group Policy

Open gpedit.msc
Go to: Computer Configuration → Administrative Templates → Windows Components → Remote Desktop Services → Remote Desktop Session Host → Connections
Set Limit number of connections to 999999 (or desired number)
Set Restrict Remote Desktop Services user to a single Remote Desktop Services session to Disabled

Via Registry

# Remove 2-session limit (requires RDS CAL license for production)
Set-ItemProperty -Path "HKLM:\SYSTEM\CurrentControlSet\Control\Terminal Server" `
  -Name "fSingleSessionPerUser" -Value 0

# Enable multiple connections
Set-ItemProperty -Path "HKLM:\SYSTEM\CurrentControlSet\Control\Terminal Server" `
  -Name "fDenyTSConnections" -Value 0

Add users to Remote Desktop Users group

# Add user to RDP group
Add-LocalGroupMember -Group "Remote Desktop Users" -Member "username"

# Verify who can access via RDP
Get-LocalGroupMember -Group "Remote Desktop Users"

RDP Disconnects After Few Seconds

Causes and solutions:

1. Session timeout active

gpedit.msc → Computer Configuration → Administrative Templates →
Windows Components → Remote Desktop Services → Remote Desktop Session Host → Session Time Limits

Set all timeout limits to Not configured or high value.

2. Network adapter in power saving mode

# Disable power saving on NIC
$adapters = Get-NetAdapter | Where-Object Status -eq "Up"
foreach ($a in $adapters) {
    $setting = Get-NetAdapterPowerManagement -Name $a.Name -ErrorAction SilentlyContinue
    if ($setting) {
        Set-NetAdapterPowerManagement -Name $a.Name -WakeOnMagicPacket Disabled `
          -ArpOffload Disabled -NSOffload Disabled -ErrorAction SilentlyContinue
    }
}

3. RDP KeepAlive not configured

# Enable RDP KeepAlive (interval in minutes)
Set-ItemProperty -Path "HKLM:\SOFTWARE\Policies\Microsoft\Windows NT\Terminal Services" `
  -Name "KeepAliveEnable" -Value 1 -Type DWord
Set-ItemProperty -Path "HKLM:\SOFTWARE\Policies\Microsoft\Windows NT\Terminal Services" `
  -Name "KeepAliveInterval" -Value 1 -Type DWord

4. Expired or locked account

See account locked section in Windows Issues.

Enable Remote Audio via RDP

To hear server audio in RDP client:

On server

gpedit.msc → Computer Configuration → Administrative Templates →
Windows Components → Remote Desktop Services → Remote Desktop Session Host → Device and Resource Redirection
→ Allow audio and video playback redirection: Enabled

In RDP client (mstsc)

Before connecting: click Show Options → Local Resources tab
In Remote audio → Settings
Select Play on this computer

Speed up Upload with RDP (slow file upload)

Slow file uploads via RDP is a known issue with "Drive Redirection" function.

Solution 1: Use FileZilla/SFTP instead of RDP copy-paste for large files.

Solution 2: Disable disk redirection in client

mstsc → Advanced Options → Local Resources → Other... → deselect Drive

Solution 3: Increase available RDP bandwidth

gpedit.msc → Computer Configuration → Administrative Templates →
Network → QoS Packet Scheduler → Limit reservable bandwidth → 0%

Analyze RDP Connection Logs

To see who connected and when:

# Last RDP connections (Event ID 4624 + logon type 10)
Get-WinEvent -LogName Security | Where-Object {
  $_.Id -eq 4624 -and $_.Message -like "*Logon Type:*10*"
} | Select-Object TimeCreated, Message | Select-Object -First 20

# Specific RDP logs
Get-WinEvent -LogName "Microsoft-Windows-TerminalServices-LocalSessionManager/Operational" | `
  Select-Object TimeCreated, Id, Message | Select-Object -First 30

# Via eventvwr.msc:
# Applications and Services Logs → Microsoft → Windows →
# TerminalServices-LocalSessionManager → Operational

RDP: Access, Port, Multi-User and Issues

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