[CamperBob2]

Frankly I've never seen any connection that didn't use keepalives stay up for very long on my LAN, much less the Internet at large.

Keepalives are a basic requirement for persistent connections. It's literally what they're for. Harmless enough solution.

[CountSessine]

That’s a bit strange though, don’t you think? TCP state only lives in the endpoints, unless you have something awful like NAT in between. Without NAT, why are keepalives a basic requirement for persistent connections?

[sonotmyname]

Without timeouts, one of the endpoints would have to maintain dead sessions indefinitely. One cannot rely on protocols to close connections properly - stuff happens.

[CamperBob2]

I run under NAT, like most Internet users in the US, although my gateway has a static IP.

No clue why the LAN drops connections without keepalive traffic. I need to get up to speed on using WireShark to diagnose dropped connections one of these days, as I actually have a couple of dropped-connection issues that need troubleshooting.

Typically I'll get a connection timeout every few days, even with keepalives, and even with a hardwired DHCP address for the MAC in question. Connections with no traffic tend to get 'cleaned up' by somebody after a few hours at most.

[innocenat]

Back before I know about SSH KeepAlive setting, I have had SSH connection going on for entire workday (~8 hours or so) on my LAN to local server.