Authoritative Resources for Public DNS Pinging

Fri Feb 11 08:31:48 UTC 2022

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.