On 2/10/22 22:20, Brian Knight via NANOG wrote:
On 2022-02-10 11:42, John Todd wrote:
"The Prudent Mariner never relies solely on any single aid to navigation"
It's best to ping multiple targets, and take action only if all targets do not return replies.
For the odd random ping just to see if routing works, sure. But as a permanent monitoring technique for an IT head and their devices, not something we want to encourage, unless that is the business of the target.
For route tracking a la $VENDOR_C's IP SLA, if possible, we'll ping next-hop IP, one target on our network, and one off our network. Withdraw the default route only if all three targets fail to return replies.
Just put this issue into context - we have a customer who (without us knowing) pings our side of the p2p link. In recent days, we've had RPD issues (a story for another day), which has forced us to re-prioritize CPU resources to RIB function, and not ICMP. The customer assumed our network was falling over, due to the increased latency from their monitoring, but we cleared that up with an explanation, as revenue traffic is unaffected. Mark.