Rollout of software probe anti farming measures
Dear RIPE Atlas users, Some of you may remember earlier discussions about this topic. We’re now ready to enable a feature to address this issue. Supporting each probe requires resources from the system; at the same time having too many probes in the same network and location does not provide much new information (that is, more probes in the same location or network would provide similar measurement results). Therefore we have controls in place to limit the amount of /software/ probes that are connecting from particular networks: 1. Each probe host can connect up to 2 software probes from the same IP address. 2. Each probe host can connect up to 4 software probes from the same IP prefix (as seen in BGP). 3. At most 32 (or 64) probes from the same IPv4 (or IPv6) prefix (as seen in BGP), regardless of the host. Software probes that connect from networks beyond these limits will not be allowed to connect, unless and until other software probes drop out. Note that we may also adjust the particular maximums over time. We realise that in some cases multiple probes belonging to the same user can come seemingly from the same network, violating rule 2 (mostly), yet they arguably still provide enough value for the community. This may be for example because they are in fact geographically widely distributed. In such a case the host can reach out to us via atlas@ripe.net with an explanation and we will consider relaxing this limit. While in the past we observed surprising corner cases, the particular limits described above are set partially taking into account the current software deployment. Therefore only a handful of probe hosts should be impacted by this (as I write this, 71 probes from 13 hosts). As I mentioned above, we’re open to adjust the limits if needed. Regards, Francesco Iannuzzelli
Hello Francesco, On Wed, 29 Apr 2026, Francesco Iannuzzelli wrote:
3. At most 32 (or 64) probes from the same IPv4 (or IPv6) prefix (as seen in BGP), regardless of the host.
does this affect AS3209 or AS3320? In the past it was very helpful to have many probes in their (large) access networks to track down a strange issue in AS3209 (different probes in the same IP prefix (as seen in BGP) showed a different behaviour).
Software probes that connect from networks beyond these limits will not be allowed to connect, unless and until other software probes drop out. Note that we may also adjust the particular maximums over time.
Will there be a clear reason in the web interface for probe hosts? Just seeing a probe as "Disconnected" (and maybe even receiving an e-mail that my probe was/is disconnected) would not be helpful from my point of view.
While in the past we observed surprising corner cases, the particular limits described above are set partially taking into account the current software deployment. Therefore only a handful of probe hosts should be impacted by this (as I write this, 71 probes from 13 hosts). As I mentioned above, we’re open to adjust the limits if needed.
How would I figure out whether I am one of the mentioned 13 probe hosts? Regards, Robert
Hi Robert thank you for your message On 29/04/2026 16:46, Robert Scheck wrote:
3. At most 32 (or 64) probes from the same IPv4 (or IPv6) prefix (as seen in BGP), regardless of the host. does this affect AS3209 or AS3320? In the past it was very helpful to have many probes in their (large) access networks to track down a strange issue in AS3209 (different probes in the same IP prefix (as seen in BGP) showed a different behaviour).
Yes we are aware of those large prefixes and the current limits have been chosen not to have impact on the number of software probes usually connected to those networks. We will be monitoring the situation, and we could enhance the algorithm in the future so that big prefixes get more leeway.
Will there be a clear reason in the web interface for probe hosts? Just seeing a probe as "Disconnected" (and maybe even receiving an e-mail that my probe was/is disconnected) would not be helpful from my point of view.
Yes we are going to add a specific tag in a future release.
How would I figure out whether I am one of the mentioned 13 probe hosts?
We are reaching out to them, via email, before enabling these measures. kind regards Francesco
participants (2)
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Francesco Iannuzzelli -
Robert Scheck