About OpenWRT, I have an old device, a Netgear WG302 v1, yes old ... 2005/2011 (I don't remember when I bought it but between 14 and 8 years old) ... but working and quite good for my use. I have already lent to help friends so sometimes I need to reset it and perform all what I have done so many years ago.
Many tips, help, links and forum post have disappeared or have been migrated or I just don't know where to find them today so I have lost so many times to search over the web sometimes for nothing.
I have today again old hardware working on my network (I think the oldest are 2x Nokia IP330 K6-2 400 MHz) but with as example a NetBSD 8 it is quite perfect to have an NTP or with OpenWRT you can get too some really good things. Even an MPD on these "grand father" to stream flac works like a charm (5x eth).
I try to keep a sort of "Hardware knowledge" base of the hardware I have. You can't imagine the time spent to find some information already found a few years ago. Now I know I have it ... but you are right sometimes it is just somewhere on the storage
Today I have a Netgear r7800 and when I find useful information (because there are so many useful information here) I try to "engrave it in marble" (french expression translated to english).
moreover I am not so young and sometimes the memory abandons me!
Sorry for this long explanation.
Thanks for the tips.
So there is a limitation per user and per hour.
I don't understand why but now I know why.
Again, thank you all for your help.