Skip to main content
ADhul.1
Associate
Dec 21, 2020 2:35 AM UTC
Question

How my device can get the list of IP address of devices in the LAN.

I read about ARP protocol but it needs IP address to get MAC. How i will know the IP address of neighboring devices to establish communication. We are using router for dynamic address.

This topic has been closed for replies.

4 replies

Tesla DeLorean
Guru
Dec 21, 2020 9:23 AM UTC

Send broadcast messages?

Snoop local traffic?​

Tips, Buy me a coffee, or three.. PayPal Venmo (See Profile) Up vote any posts that you find helpful, it shows what's working..
ADhul.1
ADhul.1Author
Associate
Dec 22, 2020 2:11 AM UTC
It is an IOT device with TCP/IP port. Once this added to the network I should be able to find out about the new device and establish the communication. I don’t have the prior info of Ip address to do that.
Jack Peacock_2
Associate II
Dec 22, 2020 6:07 AM UTC

Providing no gateway is used look at using Reverse ARP to periodically advertise the IP address associated with the MAC. The IOT device originates the broadcast message. Many early 10/100 switches required Reverse ARP to auto-negotiate 10Mbit modes, where the IOT device must provide an initial message to configure the switch.

If you are using a gateway and DHCP to assign a random IP address then you will also need a DNS which is updated by the DHCP server.

Jack Peacock

ADhul.1
ADhul.1Author
Associate
Dec 22, 2020 7:38 AM UTC
We use DHCP so I can get a dynamic IP for the new device. But for the devices who are already in the network how will they know about the IP address of this.