Around 7:30 PM PST, eskimo just stopped talking reliably to the other machines. NFS requests weren't working in either direction, and other protocols weren't working properly. I wasn't able to identify the cause. We've seen some denial of service attacks earlier in the year that exhausted all network buffers and caused similar symptoms but that was not the case tonight. The FDDI card has locked up and caused these symptoms before but always ifconfig'ing it down and then back up has restored it to service, but not the case tonight. Unable to identify the cause of the machine's failure to communicate, I rebooted it. Just as it was completing the boot process, www went off into space, it would echo what was typed but no login prompt or other response so we had to reboot it as well. These two machines are running essentially the same hardware but completely different operating systems (eskimo is SunOS 4.1.4, www is Linux 2.2.14). Everything is back up and talking but I was not able to identify the cause of this failure. The only errors printed/logged were the NFS errors resulting from the failure of the machine to communicate, and on www no errors were printed, so there is no data to use to troubleshoot this further.