How do you debug network timeouts/connection resets?

[postcd]

Hello,

i am connecting from the WIndows 10 (client) to the Linux CentOS proxy (server). And sometimes happen that server returns "Connection reset by peer" error and client returns "timed out" error.

So i am unsure where is the error. if someone want little detail about software i am running, then here. But i welcome general idea on how to discover cause. Probably using some Windows/Linux network tools or monitoring script? I can use the ping on the client, but it relly on proxy server as all my computer connections are routed via this proxy (which returns timeout). And whn proxy timeout, i can not connect it, so i assume some kind of monitoring script?

 

[timthetortoise]

Wireshark on the Windows side, tcpdump on the Linux side. Look for RST packets and retransmits. Perform a flood ping from the Linux side to the Windows side and see how much loss you have. If it's over .1% on LAN, you have something misbehaving. Could be cabling, could be failing switch/switchport, could be lots of things. If your switch is managed, check to see if you have errors on any ports involved. If you do, it could indicate a duplex mismatch somewhere, or a bad cable/NIC.