Interesting. An ICMP packet dropped when busy. Well, it seems as if there is only a hair's difference between when an ICMP packet is dropped and when an IP packet is dropped. If you are busy, you are busy, right? I know that I was getting zero packet loss for many many basic routes this time last year that are now losing packets. I think that a network is in great shape when the packet loss is at a sheer minimum. Even one percent packet loss can be felt as substantially more degraded than perfect transport. Just like ra.net, I use pings to monitor one aspect of overall performance. Me and ra.net are not alone.
On Sun, 15 Dec 1996, Forrest W. Christian wrote:
Many routers drop ICMP packets (ping, traceroute) when busy, or alternate dropping ICMP packets. I know that this behavior occurs when the packets are directed to the specific router, I am not sure if this every occurs for packets passing through. The standby tool ping needs a more reliable replacement for testing end to end packet loss.