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Blacklist IP Discovery or More flexability



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User Story

Discovery is a very powerful tool, however it needs to work on the administrators terms. I've seen this brought up before and the recommended fix is not real effective. what i'm looking for is a way to say scan this IP range, BUT exclude this ip range.

Details of User Story

When setting up discovery I've run into a problem for the past few years. our ip address range in use for most of our monitored equipment shares a range with our remote access VPN DHCP pool. i'd like to blacklist out this 50 host section of addresses. As it stands now i've got the range of addresses created and put into a group that is paused so they don't monitor, this works somewhat unless a machine goes offline before discovery finishes. it appears Discovery works by scanning IP ranges, then assigning the DNS response as the device name and then ignoring that it found an IP address. for this reason i go back through all my discovered devices and set the device name, and then change the DNS/IP to be the actual IP address. (i'm not going to go into how odd it is that the Hostname and IP address are not set on every device by default since the only place you would not want this is on DHCP devices which normally in my experience are not monitored). to this point though once the initial discovery is completed it moves on and leave the device with just a DNS name. now what appears to happen is if someone logs out of the VPN after being discovered but before discovery completes the device is listed by DNS name, does not match the existing entry for that ip address, and then starts alerting. this can get annoying since it requires constant cleanup to keep the garbage out of the alerts.

Acceptance criteria

  • discovery options for IP address Range should include a DO NOT scan Range when a larger Address Range selected such as a masked Ip address (, or a specific range, (
  • This could also be achieved by allowing the range setting to have multiple comma separated entries such as (, (although this method would be a bit more confusing and cumbersome)



add-feature improve-prtg improvement-request

Created on Nov 1, 2019 12:12:31 PM


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