i have problem with one of my machine (.35),
it doesn't show anything if i config it to local port 10001,
but if i re-config it to local port 10002,
it show syn_recv,
.35 already established connection before,
after few days,
i cant see the status in netstat( it doesn't show anything),
but i can ping it and it show good MS.
Hello,
Welcome to the forum ! We hope you find this to be a friendly and helpful place.
I have to say I'm a bit confused about what you describe. On the one hand you say that "it doesn't show anything if I config it to local port 10001". But in the screenshot you provide, we can clearly see multiple connections to TCP port 10001 in an ESTABLISHED state. So it looks as though you can connect to that port ? Or is it purely the case that you can't connect to port 10001 on the .35 IP from the .36 IP ?
Also, I take it that .36 and .35 are in fact different machines, and not multiple IPs hosted on the same machine ? If so, then you'd also want to look at the netstat output for listening services on the .35 machine, to see if when you re-configure the service to run on port 10001, if it actually starts and listens on that port (and on the .35 IP). That'll give you a better idea of what's going on that just looking at the outbound connections on the .36 machine.
As for ping - that would tell you only that you can reach the IP, it wouldn't tell you anything about the services running on that IP, or the ports that were open, closed or filtered. Ping uses ICMP (by default, anyway) rather than TCP, so the fact you can ping the host doesn't automatically mean you'll be able to hit TCP port 10001 on that host. You'll only be able to connect to 10001 on the .35 host if there is a service running on that host that is actively listening for inbound TCP connections on that port.
Anyway, hope this helps ! If you can get back to us about the above points, then we can take things from there.