Which is frustrating enough, but I’ve heard rumors that AWS’ (and other cloud) providers sometimes do weird things with routing, so ICMP doesn’t even take the same path as TCP traffic. Other times ICMP is just blocked somewhere along the way. I recommend TCPPing or similar for doing investigations.
Re:Splitting the Ping
by notyourday on Tuesday March 02, 2021 @06:48AM
(#26314277)
Just wait until you see the fun they have with edge termination where they terminate ICMP at the edge while letting TCP/UDP into the core.
Preferably to an endpoint destination that is some sort of server which isn't firewalling/rate limiting answering ICMP, and not a firewall or router.
You can see what looks like terrible loss and jitter to intermediate hops in a traceroute, but traffic to your your VoIP server that is 12.3ms away on the far side of those hops and several AS-to-AS adjacencies, might average 0.00% loss over multi week periods, with less than 0.3ms of jitter range.
Customers will also be advised to use other tools that can measure success/failure and RTT answer time of other services and daemons running on the endpoint they're testing against (at OSI layers 4-7), such as the various ways of measuring DNS lookup query time, or time to curl a sample file from an httpd over TLS1.2/1.3, and plot that on a multi day/week chart.
For their own protection routers and other network equipment with packets flowing through them deprioritize answering ICMP.