Hi all,

I am facing a weird network behavior on my Tumbleweed box.

I noticed it long ago but I just thought I was doing something wrong.

Anyway... I'll try to cut it short.

Yesterday I was updating some remote virtual server, connecting to a domain and adding Let's Encrypt certificates. The server had been inaccessible from the internet up to that moment, and I was used to connect to it through a vpn connection which made it visible under its LAN IP 192.168.1.43.

After doing my thing, I tried to connect to it through the new domain name (the VPN was disconnected). The server hosts a Wordpress installation, which almost always replies with an HTTP 301 to canonicalize the url.

Here comes the weird part: Firefox (which I had almost always used before) tried to connect to the old 192.168.1.43 IP as soon as it received the 301.
After fighting for half a day with rewrite rules on the server, it occurred to me that *maybe* it was a caching problem on the client side.

Actually, wget and curl both do the right thing: they are redirected to the expected canonicalized URL.

I tried with Falkon, which I had seldomly used with the old IP to access the server. Falkon also exhibits the caching problem, although less extensively than FIrefox (some URL forms do work, other get redirected to the old IP).

Finally, I tried with Chromium, which I never used at all. It worked perfectly.

To make sure I was not dreaming, I installed the "HTTP Header Live" addon in Firefox to actually see what was going on. The result left me stunned: after receiving HTTP 301, Firefox shows a redirect to https://192.168.1.43, and the redirect is dated Monday, 06 december 2021 *always*.

Needless to say, doing the same thing with curl/wget reports the correct redirect URL and current date/time.

I tried innumerable times to flush the DNS cache, I even stopped completely the nscd service.

BTW, the fact that each application behaves differently hints at an application-level caching (I even proceeded to flush Firefox internal DNS cache), but why are they behaving this way?

I have this same consistent behavior *now*, after closing/reopening the various applications innumerable times, even after several system reboots.
How can this be possible. What is going on under the hood?

Please help me shed some light on this behavior.

Thank you in advance

Cris