Uninitiated noon question below.
A couple of days ago, this haprogram https://programming.dev/post/41491279
Now, during the phonecall with my ISP, the guy asked, “is your router an ASUS?” to which I answered, “yes and no, because it’s sold as a router but I have it in AP mode and my actual router is OpenWrt on a Raspberry Pi.” To which he replied “noice!”
How did he know the make of my access point? A few of my own thoughts are:
- he was referring to historical data (I’ve been a loyal customer of theirs for a looong time…) from a time when I was using the same topology (setup?) but without a VPN on the router, so the hostname of the AP (stored in /etc/hostname on the ASUS OS/firmware ?) was simply displayed on whatever software an ISP uses for troubleshooting through… an ARP? But aren’t ARPs limited to a LAN/they cannot resolve beyond a hop? Or perhaps a variant of DNS? How indeed do hostnames transmit? Are they in the IP header by default?
- as in 1 above, but he actively used nmap or some other recog program
- as in 1 above but from a time when I was in fact using the ASUS machine as a router
- my VPN is “leaking” - not likely, because all my traffic either goes through the wireguard interface on OpenWrt/RPi, or it doesn’t go anywhere…
If 1, 2 or 3: why do they keep historical data on me? Is it praxis?
DHCP can also send a hostname, so it’s possible your ASUS router previously sent its hostname, and then the Pi doesn’t send one. What ever software they use might not clear the old hostname when there isn’t one.
Edit: For example, this is what my current ISP lets me see:
DHCP also sends the MAC, no?
Yep, but it’s required, and also present in every frame sent between your router and the ISP BNG.
I was trying to think of a reason why ASUS would still be showing.