# \[APP\]\[Pro\] NetScan - Track devices on your local network using ARP and TCP checks
**URL:** https://community.homey.app/t/app-pro-netscan-track-devices-on-your-local-network-using-arp-and-tcp-checks/47454
**Category:** Apps
**Tags:** app
**Created:** [May 16, 2021, 9:00am UTC](https://community.homey.app/t/app-pro-netscan-track-devices-on-your-local-network-using-arp-and-tcp-checks/47454 "2021-05-16T09:00:48Z")
**Posts on this page:** 20
**Page:** 4
### Author:  [@bayrambass](https://community.homey.app/u/bayrambass)
#### Post date: [June 1, 2022, 11:28pm UTC](https://community.homey.app/t/app-pro-netscan-track-devices-on-your-local-network-using-arp-and-tcp-checks/47454/61 "2022-06-01T23:28:29Z")
Hi @Adrian_Rockall
I find this a great app. I’m only having 1 issue.
Since I have installed Netscan I am having connectivity issues. My homey keeps going offline without a clear pattern. I then need to force restart bij replugging the cable.
When I remove the Netscan app the connectivity issues dissapear. This problem can occur 1-3 times every day.
I even reset my Homey and reinstalled firmware in the setup screen of Homey.
Do you know about this problem and what can I do about it?
---
### Author:  [@Peter\_Kawa](https://community.homey.app/u/Peter_Kawa)
#### Post date: [June 1, 2022, 11:33pm UTC](https://community.homey.app/t/app-pro-netscan-track-devices-on-your-local-network-using-arp-and-tcp-checks/47454/62 "2022-06-01T23:33:58Z")
Hi Atilla,
I don’t recognize this.
Are you sure you vary the check interval for each device?
Like, letting not all of them check every 16s at once?
---
### Author:  [@Adrian\_Rockall](https://community.homey.app/u/Adrian_Rockall)
#### Post date: [June 2, 2022, 6:05am UTC](https://community.homey.app/t/app-pro-netscan-track-devices-on-your-local-network-using-arp-and-tcp-checks/47454/63 "2022-06-02T06:05:36Z")
One of my Homey’s is very regularly going offline. Sometimes it lasts for a few seconds and sometimes for many minutes. In my case it is the Homey that’s not running Netscan that has that problem.
My good Homey is an older model (homeyModelId: “homey3d”) and the bad one is the newer (homeyModelId “homey4d”).
Could you look in the [Homey Developer Tools](https://tools.developer.homey.app/tools/system) page to see what you have?
I have reported my issues to Athom and I’m waiting to hear from them.
---
### Author:  [@Peter\_Kawa](https://community.homey.app/u/Peter_Kawa)
#### Post date: [June 2, 2022, 2:16pm UTC](https://community.homey.app/t/app-pro-netscan-track-devices-on-your-local-network-using-arp-and-tcp-checks/47454/64 "2022-06-02T14:16:36Z")
> [@Adrian\_Rockall](#):
>
> My good Homey is an older model (homeyModelId: “homey3d”)
Same model ID here and running v7.3.0.
---
### Author:  [@bayrambass](https://community.homey.app/u/bayrambass)
#### Post date: [June 30, 2022, 2:34pm UTC](https://community.homey.app/t/app-pro-netscan-track-devices-on-your-local-network-using-arp-and-tcp-checks/47454/65 "2022-06-30T14:34:24Z")
Hi Peter,
Thanks for your reaction.
I think it has to do with interval that it bugs out by checking IP adresses. Sometimes my device goes offline without losing ping on the other end of my device which is strange. I deleted it because I need my automation to work. I had no problems untill I tried it again today. And after an hour the Homey crashed. I can’t check logs myself unfortunately.
Is it best practice to change all the “Check interval” and all other checks? They are all standard the same value in my Homey.
Yours sincerely,
Bayrambass
---
### Author:  [@Adrian\_Rockall](https://community.homey.app/u/Adrian_Rockall)
#### Post date: [June 30, 2022, 4:35pm UTC](https://community.homey.app/t/app-pro-netscan-track-devices-on-your-local-network-using-arp-and-tcp-checks/47454/66 "2022-06-30T16:35:00Z")
I have Netscan checking 4 device at the default intervals and have no problems, so, unfortunately, I have no idea why it is causing you problems.
Could you look at the memory usage for the app in Insights to see if something is happening there?
---
### Author:  [@bayrambass](https://community.homey.app/u/bayrambass)
#### Post date: [July 11, 2022, 6:40am UTC](https://community.homey.app/t/app-pro-netscan-track-devices-on-your-local-network-using-arp-and-tcp-checks/47454/67 "2022-07-11T06:40:02Z")
Hi Adrian,
It has been around three weeks that I have change some of the intervals. I didn’t have the problem anymore since 29th of june. You can see that the memory drop is significant. I don’t exactly know what the empty spaces are between 3rd and 8th of july. It could be my Homey powered off.
Since changing the interval Homey didn’t crash anymore and I hope it will not anymore. You can see the chart for more details.
---
### Author:  [@Marcel\_Visser](https://community.homey.app/u/Marcel_Visser)
#### Post date: [July 25, 2022, 3:28pm UTC](https://community.homey.app/t/app-pro-netscan-track-devices-on-your-local-network-using-arp-and-tcp-checks/47454/68 "2022-07-25T15:28:32Z")
Hi,
I am trying to add my desktop pc, but my firewall is blocking the connection. I tried to open a port, but my there is still no connection. I tried the app Fing to check open ports and there are 0. Really strange because I openen ports in Windows. DO you have any idea what to do?
---
### Author:  [@Adrian\_Rockall](https://community.homey.app/u/Adrian_Rockall)
#### Post date: [July 25, 2022, 3:45pm UTC](https://community.homey.app/t/app-pro-netscan-track-devices-on-your-local-network-using-arp-and-tcp-checks/47454/69 "2022-07-25T15:45:19Z")
If the firewall is completely masking the connection then the only option is to fix the firewall.
On my PC the firewall rejects the connection so the app can see the PC is there otherwise the connection times out.
Could you send the log from th Configure App screen so I can see the failure mode?
---
### Author:  [@Marcel\_Visser](https://community.homey.app/u/Marcel_Visser)
#### Post date: [July 25, 2022, 5:28pm UTC](https://community.homey.app/t/app-pro-netscan-track-devices-on-your-local-network-using-arp-and-tcp-checks/47454/70 "2022-07-25T17:28:55Z")
Thanks for your reply… It had something todo wich port I was using. I tried different ports and finally found one with a good reliability. So it is working fine now!
---
### Author:  [@Henk\_Renting](https://community.homey.app/u/Henk_Renting)
#### Post date: [February 8, 2023, 2:08pm UTC](https://community.homey.app/t/app-pro-netscan-track-devices-on-your-local-network-using-arp-and-tcp-checks/47454/71 "2023-02-08T14:08:43Z")
@Adrian_Rockall:
Can we have a action flowcard that checks if devices are online?
So:
IF this flow is started (i.e)
THEN run connection check for device X
This one would be nice too:
THEN run connection check for all devices
After a manual repair of a device that has lost connection, it would be nice to reset the alarm this way…
---
### Author:  [@Adrian\_Rockall](https://community.homey.app/u/Adrian_Rockall)
#### Post date: [February 8, 2023, 6:47pm UTC](https://community.homey.app/t/app-pro-netscan-track-devices-on-your-local-network-using-arp-and-tcp-checks/47454/72 "2023-02-08T18:47:34Z")
Hmm, I’m not sure it will save much as the app is constantly checking anyway.
What do you have your check interval set to?
---
### Author:  [@Henk\_Renting](https://community.homey.app/u/Henk_Renting)
#### Post date: [February 8, 2023, 7:14pm UTC](https://community.homey.app/t/app-pro-netscan-track-devices-on-your-local-network-using-arp-and-tcp-checks/47454/73 "2023-02-08T19:14:43Z")
Thx for the quick reply.
I had set it to a rather large interval, but I could shorten it indeed.
My idea was to use a larger interval for less important devices. When set to a large interval, it would be nice to have such a flow to let Netscan check immediatly after a network problem is resolved…
Another nice flowcard to have would be:
IF a device disconnected
with a logic card containing it’s name or IP-address.
That way you don’t have to make a flow for every device, but you can have Homey report a device is offline with a variable containing which one it is…
Just ideas… 😉
---
### Author:  [@Sharkys](https://community.homey.app/u/Sharkys)
#### Post date: [February 19, 2023, 9:44pm UTC](https://community.homey.app/t/app-pro-netscan-track-devices-on-your-local-network-using-arp-and-tcp-checks/47454/74 "2023-02-19T21:44:05Z")
Hi @Adrian_Rockall , not sure if anyone has reported but seems that Invert action in the Flows and Advanced flows does nothing… below is example with AND condition - in this case IS OFFLINE.
…do you think you can fix it please ?
---
### Author:  [@Adrian\_Rockall](https://community.homey.app/u/Adrian_Rockall)
#### Post date: [February 19, 2023, 9:50pm UTC](https://community.homey.app/t/app-pro-netscan-track-devices-on-your-local-network-using-arp-and-tcp-checks/47454/75 "2023-02-19T21:50:02Z")
For the advanced Flow you need to connect to the bottom output for the offline, e.g. online is false. For normal Flows the invert setting is done by Homey.
---
### Author:  [@Sharkys](https://community.homey.app/u/Sharkys)
#### Post date: [February 19, 2023, 9:53pm UTC](https://community.homey.app/t/app-pro-netscan-track-devices-on-your-local-network-using-arp-and-tcp-checks/47454/76 "2023-02-19T21:53:03Z")
Ah, interesting, didn’t think about that but makes sense 😉 I was just used to see Invert = Online/Offline 😉 Thank you.
---
### Author:  [@Adrian\_Rockall](https://community.homey.app/u/Adrian_Rockall)
#### Post date: [February 20, 2023, 1:41pm UTC](https://community.homey.app/t/app-pro-netscan-track-devices-on-your-local-network-using-arp-and-tcp-checks/47454/77 "2023-02-20T13:41:11Z")
I have just realised what you mean about the Invert option for the And card. I will look into that as it doesn’t look right.
---
### Author:  [@Adrian\_Rockall](https://community.homey.app/u/Adrian_Rockall)
#### Post date: [February 20, 2023, 4:51pm UTC](https://community.homey.app/t/app-pro-netscan-track-devices-on-your-local-network-using-arp-and-tcp-checks/47454/78 "2023-02-20T16:51:14Z")
I have published a new test version.
---
### Author:  [@Sharkys](https://community.homey.app/u/Sharkys)
#### Post date: [February 20, 2023, 5:07pm UTC](https://community.homey.app/t/app-pro-netscan-track-devices-on-your-local-network-using-arp-and-tcp-checks/47454/79 "2023-02-20T17:07:27Z")
Seems to be working fine, Invert now changes from online to offline. Thank you 😉
---
### Author:  [@Emiliano\_Quetimporta](https://community.homey.app/u/Emiliano_Quetimporta)
#### Post date: [February 8, 2024, 5:16pm UTC](https://community.homey.app/t/app-pro-netscan-track-devices-on-your-local-network-using-arp-and-tcp-checks/47454/80 "2024-02-08T17:16:59Z")
Having the same issue any tip which port to try?
[Previous page](https://community.homey.app/t/app-pro-netscan-track-devices-on-your-local-network-using-arp-and-tcp-checks/47454.md?page=3)
[Next page](https://community.homey.app/t/app-pro-netscan-track-devices-on-your-local-network-using-arp-and-tcp-checks/47454.md?page=5)