Network issues I’ve experienced: STP taking too long to enable forwarding between network stack reloads, poor quality network wire or damaged runs (this is where I experienced your exact error message, it will work on dhcp, but fail on bigger packets), and amazingly enough, bugs in the switches (in my case, Cisco SG200’s with layer3 protection that could not be disabled - a firmware fix is available now) that caused issues with UDP on privileged port ranges (NFS), and slow DHCP servers.
