Hi Christopher,

thanks for the explanation, this makes sense!

In general you can consider a probe with a "connected" status, but none of (ipv4-works, ipv6-doesnt-work, ipv4-works, ipv6-doesnt-work), as having a problem submitting results due to some other issue.

Can we have a system-tag for this case too, instead of leaving the probes untagged?
For example:

"IPv4 issue suspected"
"IPv6 issue suspected"
"connection issue suspected" (for DNS results not delivered)


This would help to make the probe hosts aware of problems.
Leaving probes untagged is a bit... vacuous.
In addition, the explanation you've provided here should be included in the official Atlas documentation (i wasn't able to find anything).


Thanks & best regards,
Simon



On 05.03.25 13:40, Christopher Amin wrote:
On Wed, 5 Mar 2025 at 13:22, Simon Brandt via ripe-atlas <ripe-atlas@ripe.net> wrote:
ipv6-works check (three possible cases):

1. tagged: system-ipv6-works
2. tagged: system-ipv6-doesnt-work
3. untagged (none of the above tags is set)

I don't see the purpose of the untagged status. Either IPv6 / IPv4 works, or not. What is the completely untagged status supposed to tell me?

A "doesnt-work" tag is applied if the probe returns results for (in this case) some IPv6 measurements, and all of those results indicate a failure to reach the targets. If, on the other hand, the probe has a problem submitting results to the controller, then we don't know whether it can or cannot reach IPv6 targets, so it doesn't get either tag. In general you can consider a probe with a "connected" status, but none of (ipv4-works, ipv6-doesnt-work, ipv4-works, ipv6-doesnt-work), as having a problem submitting results due to some other issue.
 
The same applies to DNS checks. There's a tag for every case, plus the "no-tag status":

DNS resolving check:

1. tagged: system-resolves-a-correctly
2. tagged: system-resolves-a-incorrectly
3. tagged: system-doesnt-resolve-a
4.
untagged (none of the above tags is set)

Similar to above:

1. The DNS record returned is as expected
2. A DNS record is returned, but it is not the one expected
3. No DNS record could be returned
4. The relevant measurement results were not submitted