Devices blocked from each other on LAN

[jwhite518]

I'm trying to connect from one laptop on my network to another using an app that runs on port tcp/27401. I know the app is running and the port is up and listening. (validated with netstat.) But I can't connect. By way of troubleshooting I tried a simple ping from A to B, and that isn't working either. Is there some setting on the ORBI that prohibits LAN devices from seeing each other?

(One is on the 2.4Ghz WiFi and the other is on the 5Ghz WiFi, if that makes any difference.)

This is an odd question because I know some devices can see each other. I have a network printer that multiple devices can print to.

[CrimpOn · Accepted solution]

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@jwhite518 wrote:

I'm trying to connect from one laptop on my network to another using an app that runs on port tcp/27401. I know the app is running and the port is up and listening. (validated with netstat.) But I can't connect. By way of troubleshooting I tried a simple ping from A to B, and that isn't working either. Is there some setting on the ORBI that prohibits LAN devices from seeing each other?

(One is on the 2.4Ghz WiFi and the other is on the 5Ghz WiFi, if that makes any difference.

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The Guest WiFi has a provision to prohibit devices from contacting each other.  My assumption is these devices are not on the Guest network.

2.4G vs. 5G has no relevance.

Windows computers default to "not respond to ICMP (ping)", which could explain not being able to ping in one (or both) directions.

Do you have a network scanner program that can test for open ports?

[FURRYe38]

Do you have any access controls, Armor or Circle enabled? 

[CrimpOn · Accepted solution]

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@jwhite518 wrote:

I'm trying to connect from one laptop on my network to another using an app that runs on port tcp/27401. I know the app is running and the port is up and listening. (validated with netstat.) But I can't connect. By way of troubleshooting I tried a simple ping from A to B, and that isn't working either. Is there some setting on the ORBI that prohibits LAN devices from seeing each other?

(One is on the 2.4Ghz WiFi and the other is on the 5Ghz WiFi, if that makes any difference.

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The Guest WiFi has a provision to prohibit devices from contacting each other.  My assumption is these devices are not on the Guest network.

2.4G vs. 5G has no relevance.

Windows computers default to "not respond to ICMP (ping)", which could explain not being able to ping in one (or both) directions.

Do you have a network scanner program that can test for open ports?

[jwhite518]

Access Control is off. Armor was on and I turned it off and rebooted the router. Same result - no ping, and can't use the custom app. I know that host is communicating on the network -  I can see a few packets from it in wireshark. Does Orbi block ICMP on the LAN?

[CrimpOn]

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@jwhite518 wrote:

Does Orbi block ICMP on the LAN?

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Definitely not.  I ping my devices all the time.

[jwhite518]

Ta Daa! That was the answer. Windows Firewall. I added a rule to allow my app port, and now all is well. Thanks!

I didn't realize that Windoze blocks ICMP by default.