I haven't found any documentation on a limit. I bet it depends on the hardware. What hardware and how many probes do you need?
You can view how the probes are impacting the CPU by displaying processes. A "PING Client" will be indicated for each probe on the unit.
1335a#show processes cpu | include PING
17966 PING Client 16 W 108 71 0 0.00
17968 PING Client 16 W 101 71 223 0.02
17970 PING Client 16 W 30 72 0 0.00
At the time of this post, AOS allows for ten probes of each type to be configured at the same time, regardless of hardware platform. You can configure a total of fifty active probes at once (ten of each type (ICMP, HTTP, etc.)).
I hope that makes sense, but please do not hesitate to reply to this post with any additional questions. I will be happy to help in any way I can.
I went ahead and flagged the "Correct Answer" on this post to make it more visible and help other members of the community find solutions more easily. If you don't feel like the answer I marked was correct, feel free to come back to this post to unmark it and select another in its place with the applicable buttons. If you have any additional information on this that others may benefit from, please come back to this post to provide an update. If you still need assistance, we would be more than happy to continue working with you on this - just let us know in a reply.