Re: 60+% ping packet loss on Pi3 under -current and stable-13

On Apr 29, 2022, at 7:12 PM, bob prohaska <fbsd@www.zefox.net> wrote:
> 
> Since about December of 2021 I've been noticing problems with
> wired network connectivity on a pair of raspberry pi 3 machines
> using wired network connections. One runs stable-13.1, the other
> runs -current, both are up to date as of a few days ago.
> 
> Essentially both machines fail to respond to inbound network
> connections via ssh or ping after reboot. If I get on the 
> serial console and start an outbound ping to anywhere, both
> machines respond to incoming pings with about a 65% packet
> loss. Ssh connections are answered with delays of zero to
> perhaps thirty seconds. Once connected ssh is usable but
> erratic, with dropped characters, multi-second delays and
> disconnects after random intervals from minutes to hours.
> 
> There are five other Raspberry Pi's on the network. Three
> Pi2's run 12.3-stable, one Pi2 runs -current and a Pi4 runs
> -current. All have no problems pinging one another and out
> of network, so there's nothing obviously wrong with the net.
> The network is not routed, but rather a block of eight
> addresses simply bridged from my ISP over DSL.
> 
> It's been found that an image of 13.1-RC4 behaves similarly
> on one Pi3 when on the public network but exhibits more normal
> ping response when moved to a 192.168.1.n private network. On
> the face of it, this seems significant, but I can't guess how.

Suggest running tcpdump on the rpi3 to see what is going on
when connected to the public vs private net.