TCPPing: https://netbeez.net/blog/tcping/
vmPing: <https://netbeez.net/blog/how-to-use-vmping/>
DNSPing: <https://netbeez.net/blog/dnsping-linux/>
PathPing: <https://netbeez.net/blog/path-analysis-pathping-windows/>
fping: <https://netbeez.net/blog/linux-how-to-use-fping/>
gping: <https://netbeez.net/blog/linux-how-to-use-gping/>
prettyping: <https://netbeez.net/blog/linux-how-to-use-prettyping/>
https://www.google.com/search?client=firefox-b-e&q=smokeping...
If you have a network monitoring or asset system you can export IP addresses from, you should use a small glue script to automatically build a smokeping configuration. I've got one for our LAN and one for the WAN at each of our sites so I can track down issues at either level.
The LAN connection charts are a great daily sanity check, and the WAN connections (I have every-to-every for each site so any and all inter-site issues can be seen) can help keep your ISP honest with the service they're delivering.