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I have run into a snag regarding MAC addresses, or retrieving them from devices. I don't know if this is the correct forum for this question, but it is the best that comes to my mind. Background: I have created a GUI that communicates with a PCB that has a standard Ethernet port (wired). My GUI searches for available IP addresses, and then retrieves the MAC address for each of these, using the WinAPi.IpHlpApi SendARP function. The 36 most significant bits of the MAC address are then used for filtering. Recently, my lab has been moved to a new location, with no wired access to the Router / DHCP server. Since my PCB only has a standard wired Ethernet port, I have set up an access point in "client mode", to make a tiny wired network in the lab. (TP-Link WA801N) This seems to work nicely, except... The problem: My GUI cannot find the PCB, and I've figured out that the reported MAC address is wrong when the PCB is connected to the access point. I can find the board's IP address with Advanced IP Scanner, but the reported MAC address is the same as the access point's MAC address. For security, I have partially obscured the MAC addresses, but the two MAC addresses marked with yellow are identical. The DOS command arp -a says basically the same thing. However, if I connect a computer to the same ethernet switch as my PCB (with a network cable), then I get the correct MAC address through that connection. Can anyone explain what is going on here? Is it natural that an access point overrides the MAC addresses of the connected devices? Could there be some obscure setting that I need to change? Or is there something wrong with the access point? Any help will be greatly appreciated.

Hi, I am writing a piece of software, that needs to find specific devices on a LAN. The functionality I need is more or less a scaled-down version of "Advanced IP Scanner", or similar software. My intention is to connect to all devices in a subnet, one at a time, and get the MAC address from each device. I can determine if a device is of interest based on the 36 most significant bits of the MAC address. Now, how do I do that? I have found a number of examples that give me the MAC address of my own computer, such as this: And other examples that don't tell much about what they actually do, such as this: https://www.swissdelphicenter.ch/en/showcode.php?id=651 Does anyone around here know how to get the MAC address of devices on a LAN in Delphi?

You may have noticed that the OpenSSL 1.1.1 series will reach End of Life (EOL) next Monday... Most sensible options are to switch to 3.0 or 3.1 as soon as possible. But we also discovered that switching to OpenSSL 3.0 could led into big performance regressions... so which version do we need to use? 😮 I just published a blog article about this, and also how we tried to leverage any incompatibility issue within the mORMot OpenSSL layer: https://blog.synopse.info/?post/2023/09/08/End-Of-Live-OpenSSL-1.1-vs-Slow-OpenSSL-3.0