I have an older iMac still running High Sierra 10.13.6 as that is as high as it can go. I use it as a server for our household (backups and other stuff) but it is regular MacOS (not Server). Every two weeks like clockwork on a Friday (and it seems to always happen on Friday even if it's been rebooted for some other reason so it doesn't seem to be happening after being up about 336 hours), it starts experiencing intermittent network errors. I know this because I have various scripts that check network status (are other machines on the network up? Has my external TCP/IP address been changed? and others). The scripts run under Cron and when they experience an error, send me an email (despite the network issues, which are intermittent, the email makes it out). As near as I can tell, they all come from the dig command which is used to query a name server.
For instance, when this problem is occurring, the command (this is a Terminal command in my script):
dig @192.168.0.70 host.example.com > /dev/null
generates the error:
/BuildRoot/Library/Caches/com.apple.xbs/Sources/bind9/bind9-57.3/bind9/lib/isc/unix/socket.c:2132: internal_send: 192.168.0.70#53: Network is down
(this command is checking if the name server I run on 192.168.0.70 is running)
When this happens, I immediately reboot it as if I don't, the backups that run that night (using Retrospect to backup the other computers across the network) will most likely fail due to the network issues. I suspect the message I see is a symptom of some other and deeper issue.
Anyone seen anything similar?
For instance, when this problem is occurring, the command (this is a Terminal command in my script):
dig @192.168.0.70 host.example.com > /dev/null
generates the error:
/BuildRoot/Library/Caches/com.apple.xbs/Sources/bind9/bind9-57.3/bind9/lib/isc/unix/socket.c:2132: internal_send: 192.168.0.70#53: Network is down
(this command is checking if the name server I run on 192.168.0.70 is running)
When this happens, I immediately reboot it as if I don't, the backups that run that night (using Retrospect to backup the other computers across the network) will most likely fail due to the network issues. I suspect the message I see is a symptom of some other and deeper issue.
Anyone seen anything similar?