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.
