Buyer Wants Mac Address and Serial Number of Router

[this-that-and-then-some]

A buyer is asking for the Mac Address and Serial Number off of our AT&T router.  Not sure if we should provide that or not, is there a risk if we do?

[repairelectronics]

I think your question may be moot since the pictures in your listing show all that information.

The buyer may have wanted the numbers so they could check with ATT to see if the router was blacklisted for some reason.

I am not an expert in that field but MAC addresses can be spoofed, it is one of the things that software looks at as a license key, Microsoft uses it as one of the tell tales so you can not load their OS on multiple machines.

You could always call ATT tech support to ask their opinion.

[omgitlightsup]

The MAC address is one good way to tell the software revision in the modem. There's not much that the buyer can do to defraud you with it. 

Part of the MAC identifies the manufacturer of the device, and the other half is like a serial number.

One "trick" commonly done with MAC addresses, if you get, say, your IP address banned from a web forum, is to change the MAC address in the device (it can usually be reprogrammed quite easily), which prompts the cable company to give you a new IP, so you can skirt your ban. 

MAC addresses are part of OSI layer 2, which controls internet communication on a single network link (in this case, your cable line). If two devices have the same MAC address, it causes problems, but this almost never happens in real life unless you screw something up inside your house. I don't think there's a blacklist on MACs.. it would be on the serial code of the modem.

I would be curious as to why they want to know, but I believe it's just so they can establish the date of manufacture or exact specs of the device.