Suggestions for Gateway monitor IPs
We have been using the Google IPs 184.108.40.206 and 220.127.116.11 as monitor IPs. However, Google now has some sort of presence here in Nepal. We, reasonably often (e.g. all last night), have instances where an ISP network has internal connectivity all around Nepal, our inter-office VPN links are up, and we can ping 18.104.22.168 and 22.214.171.124, because they route to somewhere in Nepal. We can even do Google searches, but clicking on the results fails because there is no connectivity out of Nepal. e.g. last night the ISP screwed up their routing somehow and we got TTL expired in transit. A traceroute showed the packet bouncing back and forth between 2 of the ISP routers in towns near the Indian border.
At this time, there were other ISPs that could "escape" Nepal - so failover was possible if the fault condition was detected.
I need monitor IPs that:
a) Are hosted only in "major countries" (Europe, North America, SE Asia) - thus their presence indicates reach-ability across some real functional internet backbone.
b) Are reliable themselves
c) Respond to ping
I'm sure there are many many others.
I suppose you could also ping the NTP time servers by IP per country or region…
For example... 126.96.36.199
Some such servers don't like to get pinged every millisecond, so maybe like every 5 or 10 seconds.
For your purposes, 188.8.131.52 (or another reliable NTP server) is probably better than a DNS IP.