This is Scientific Linux 7.3 (derived from RedHat Enterprise Linux 7.3), on VMware Fusion 11.0.2, running on Mac OS High Sierra (10.13.6). The guest uses NAT networking.
My program uses libnss_dns.so, and starting the program involves initializing that library. Using the Fusion nameserver (172.16.198.2), that takes 10 seconds -- DISASTER. When I change /etc/resolv.conf to use the same nameserver my Mac uses, program startup is instant.
I could live with that, as I have no need to do DNS lookups on local hosts. But the NetworkManager keeps changing it back! (After every pause/resume, perhaps other times)
I do not know the internals of that library, or what specific aspect of the DNS causes the delay; "nslookup vmware.com" responds instantly. BTW a High Sierra guest running the same program (built for a Mac) does not have this problem.
How can I fix this? -- either getting 172.16.198.2 to not delay program startup, or configure the NetworkManager to use a better DNS (or at least stop resetting to the bad one).