Windows Server to Server Communication Troubleshooting

When trying to see what devices a Windows Server is communicating with on the network, there are several approaches you can take:

1. Network Traffic: Use network monitoring tools to inspect the network traffic. Tools like Wireshark can capture and analyze network packets, which can help you see which devices are communicating with your server.

2. Ports: Netstat is a powerful command-line tool that displays active TCP connections, ports on which the computer is listening, Ethernet statistics, the IP routing table, IPv4 statistics (for the IP, ICMP, TCP, and UDP protocols), and IPv6 statistics (for the IPv6, ICMPv6, TCP over IPv6, and UDP over IPv6 protocols). You can use it to see what ports are open and what connections are currently active. The command `netstat -ano` is particularly useful.

3. Event Logs: Windows servers maintain a set of event logs that track various activities. The ‘Windows Logs’ category in the Event Viewer includes the ‘Security’ log, where you can find events related to network activities.

4. Firewall Logs: If the Windows Server is configured with a firewall, the firewall logs can show which connections have been allowed or denied.

5. Resource Monitor: You can use the Resource Monitor tool in Windows to see what network connections a particular process is making. To open Resource Monitor, you can type “resmon” into the Start Menu search or the Run dialog (Win+R).

6. PowerShell Cmdlets: PowerShell offers several cmdlets that can provide information about network connections. `Get-NetTCPConnection` is one such cmdlet.

Remember to always follow your organization’s policies and procedures when it comes to network monitoring and analysis, to respect privacy, legal, and ethical guidelines.


Sure, here are examples of each approach:

1. Network Traffic: For using Wireshark, you would first need to install the software. Once installed, you can start a new capture session, specifying the network interface to capture on. The captured traffic can then be analyzed using various filters. For example, you might filter by IP address or protocol to narrow down the data you’re looking at.

2. Ports: You can use the `netstat` command in Command Prompt. Here’s an example command that displays active TCP connections, the PID, and the process name:

netstat -ano | findstr :{PortNumber}

Replace {PortNumber} with the port number you’re interested in. The output will list all active connections on that port, along with the associated PID. You can then use Task Manager or the `tasklist` command to find out which process corresponds to that PID.

3. Event Logs: In Event Viewer, you can go to ‘Windows Logs‘ > ‘Security‘ to view the security event log. You might filter for event ID 5156 (“The Windows Filtering Platform has permitted a connection“), which indicates a permitted network connection.

4. Firewall Logs: The Windows firewall logs are usually located in `systemroot\system32\LogFiles\Firewall\pfirewall.log`. You can open this file in a text editor or log viewer to inspect it. The file will contain entries for both allowed and denied connections.

5. Resource Monitor: Open Resource Monitor (by typing “resmon” into the Start Menu search or the Run dialog), then go to the ‘Network‘ tab. Here you can see which processes are using network resources, and by expanding a process, you can see which IP addresses it’s communicating with.

6. PowerShell Cmdlets: The `Get-NetTCPConnection` cmdlet can be used to display active TCP connections. For example, you could use the following command to see active TCP connections:

Get-NetTCPConnection | Where-Object { $_.State -eq 'Established' }

This command filters the output to show only established TCP connections. The output includes the local and remote IP address and port number for each connection, as well as the process ID (PID) that owns the connection.

Remember, these are just examples. Your usage of these tools may differ based on your specific needs. Always follow your organization’s guidelines and policies when using such tools.