> Used to have similar finger pointing with our network team...
Me too. Our servers had multiple NICs for different traffic types (users, inter-server comms, backups). A regular issue was various switch ports getting "hung". The quick troubleshooting fix was to get the network team to reset the switch port. I say "quick" - the conversations invariably went:
Networks: Please reboot the server to check the problem isn't at your end.
Me: That will take at least 20 minutes and cause wider disruption; We've seen this issue multiple times, and the quick troubleshooting fix is for you to remote in and reset the switch port. I can tell you exactly which switch & port it is. It will take you 2 minutes. Or I can escalate to $TECHDIRECTOR.
Networks: <grumble , grumble> We've checked the port and there are no errors.
Me: Thank you. Did you reset it? Because the errors went away during our conversation.
Networks: No, no, we just checked it. The network is never the problem...
Me: [knowing they had reset the port] Cool, thanks. As you can't find any errors that indicate the server/NIC, we'll keep "reset the switch port" at the top of our troubleshooting checklist.
On one memorable occasion a switch for backups traffic hung completely so all servers using that switch were impacted - Guess what, Networks suggested rebooting all the servers (-‸ლ)