TCP-forwarding with netcat - weird failures ...

[Eugene Grosbein]

04.03.2019 17:43, Patrick M. Hausen wrote:

> Needless to say: doesn’t work. And no, it’s not the obvious ARP caches.
> Connections can be established but then abort spontaneously without
> an observable pattern or reason.

Each "abort" of TCP connection has its own distinct reason:
TCP FIN or TCP RST or ICMP unreach or timeout etc.

You need to start collecting packet captures with "tcpdump -npw file.pcap"
Without such details, noone can tell you what's your reason out of hundreds possible.