OpenWrt reports a different IPv6 than sites like whatismyip.com

The address in the red box is what OpenWrt says my current public IPv6 address is, but when I use sites like https://www.whatismyip.com/, it tells me a slightly different address. Why might this be?

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I'm not sure which part of the IP addresses are actually sensitive or not, so I err on the side of caution.

I'm using a Linksys WRT32X router connected to my ISP's modem set to bridge mode. I have cable internet using DOCSIS 3.0, I believe. I'm pretty unfamiliar with how IPv6 works, but the IPv4 address reported by OpenWrt is correct, so I'm surprised the IPv6 one isn't.

It probably is the address below the one you indicate.

The /128 address is usually the address of the WAN interface.

The public IP address is the address of LAN (there is no WAN <> LAN NAT so your public IP address is not the WAN ip address)

Somewhere around here is a very good explanation, how IPv6 works I will see if I can find it, will also refresh my knowledge :slight_smile:

IPv4 is using masquerade on wan interface, IPv6 is working end to end without translations. If you are using the browser of a lan host to find your IPv6, it will not match the one of the wan6 interface.
The /128 IPv6 on wan6 is assigned by DHCPv6, the /64 is assigned by SLAAC.
Since you have a delegated prefix and lan gets a chunk from this, you'll see the IPv6 of lan interface if you try to query your IPv6 from the OpenWrt.

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The IPv6 shown by the site should match the current IPv6 of the host running the web browser.

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You are absolutely right. I had no idea. I used icanhazip.com from my browers, phone, and the OpenWrt console and got different addresses for each.

Thanks for pointing this out!

You are right, it is the second address line, not the first. dave14305 pointed out that sites will return a different IPv6 per host, which I hadn't realized.

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