Arp does not show all

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Arp does not show all
Arp does not show all
2021-03-05 05:31:59
Model: Archer A10
Hardware Version:
Firmware Version:

I have an Archer A10.

I would like to be able to view the connected clients table (MAC address and IP).

From my PC on the network I issue an "arp -a" command from a Windows 10 command window.

The output I get shows the clients connected to 2.4 GHz, but none of the clients connected to 5 GHz.

If I open the TP-Link browser interface and look at Advanced-Network-DHCP-server, I do see the 5 GHz clients.

 

What am I doing wrong?

 

Thanks,

Barry.

 

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Re:Arp does not show all
2021-03-05 18:42:56 - last edited 2021-03-05 18:57:41

@canalrun 

 

Same here, different router, an Archer A20.

 

I also have NEW VIEW problems occasionally (USB External power 4TB drive connected to the router) presenting an Error 52.

 

Try NET VIEW on your W10 PC in a CMD prompt, does that work?

 

I have to suspect Win10 or possibly the router?

 

However, I can't find anything Googling like this?

 

I did find one that said you had to run PING on the .255 IP Address to populate the list on your PC, and ARP -a.

 

I tried this,

 

C:\>ping 192.168.0.255

Pinging 192.168.0.255 with 32 bytes of data:
Reply from 192.168.0.122: bytes=32 time=184ms TTL=64
Reply from 192.168.0.122: bytes=32 time=96ms TTL=64
Reply from 192.168.0.122: bytes=32 time=101ms TTL=64
Reply from 192.168.0.122: bytes=32 time=106ms TTL=64

Ping statistics for 192.168.0.255:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss)
Approximate round trip times in milli-seconds:
    Minimum = 96ms, Maximum = 184ms, Average = 121ms

 

and I did get ONE more device in the list. However, I have a some IoT's that didn't show. Still, checking against the DHCP list, it appears I didn't get all of them?

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Re:Arp does not show all
2021-03-05 20:20:54

@IrvSp  Thanks for the reply.

 

Yes, I also found that one needed to ping the ….255 address before issuing an "arp -a". But it still only shows the 2.4 GHz band clients, none of the 5 GHz band clients.

 

I'm just guessing, and I probably have the terminology wrong – I think it might have something to do with the fact that the router implements the 2.4 GHz band as one interface and the 5 GHz band as the second interface. The arp command only looks at the first interface???

 

I wonder if there is another way to get the client list from the router programmatically. Do you know if the router responds LAN HTTP Get commands?

 

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Re:Arp does not show all
2021-03-05 22:27:30

@canalrun 

 

Yes, but it isn't PRETTY and might not even be completely possible?

 

There IS a GETMAC Windows command...

 

See https://www.windows-commandline.com/get-mac-address-command-line/

 

However, to get a list, it could be a PAIN as the only way to 'sneak' onto a remote device on the LAN is to be allowed to access it. Either the device would have to have NO requirement for a User ID and Password, or you have to have permission/account on that device. Of course many will not honor the command.

 

If you wanted to do it, build a CMD file that does 252 iteration incrrementing the IP Address last octet by 1 starting with 2. Write to a file, and then scrape the file for IP's that responded....

 

I don't even know if an IoT would respond at all?

 

Could also programmitcally open a browser, log onto the router, get to the DHCP page, 'scrape' that, and go on until you got them all... that too would be a major undertaking I'd think?

 

This program (costs money) might work and do that as well, https://lizardsystems.com/find-mac-address/

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Re:Arp does not show all
2021-03-06 00:28:49

Thanks @IrvSp  I will take a closer look at this stuff.

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