I have to scan a class B network with a lot of unreachable ip address.

How can I speed up scanning (by lowering both retry count and timeout)?

Article Comments

If the device is not pingable at all, it will immediately move on. Did you already start the scan and observed slowdowns? There are 65,536 possible addresses in a class B network, it may take some time to iterate through it. One could also create multiple groups reflecting the various subnets using PRTGapi (see my signature) and discovery them seperately.

PRTGapi | Feature Requests | WMI Issues | SNMP Issues

Kind regards,
Stephan Linke, Tech Support Team


Mar, 2019 - Permalink

Yes, I started it yesterday. I used Autodiscovery with Template, by choosing only ping. Most ip address are not used, but unfortunately the subnet is really a /16 one. After many many hours (maybe 12?) it only reached 57%.

What does mean the following "13 seconds" delay between logs?

2019-03-27 16:19:14.114313 INFO TId    1640 CoreAutoDiscovery> 27/03/2019 16:19:14: Bulk Ping; Group ID: 5365; 
FOUND: 0Devices

2019-03-27 16:19:27.551840 INFO TId    1640 CoreAutoDiscovery> 27/03/2019 16:19:27: Bulk Ping; Group ID: 5365; 
FOUND: 0Devices

2019-03-27 16:19:40.536259 INFO TId    1640 CoreAutoDiscovery> 27/03/2019 16:19:40: Bulk Ping; Group ID: 5365; 
FOUND: 0Devices

2019-03-27 16:19:53.114405 INFO TId    1640 CoreAutoDiscovery> 27/03/2019 16:19:53: Bulk Ping; Group ID: 5365; 
FOUND: 0Devices

2019-03-27 16:20:06.130034 INFO TId    1640 CoreAutoDiscovery> 27/03/2019 16:20:06: Bulk Ping; Group ID: 5365; FOUND: 0Devices

2019-03-27 16:20:19.583191 INFO TId    1640 CoreAutoDiscovery> 27/03/2019 16:20:19: Bulk Ping; Group ID: 5365; FOUND: 0Devices

2019-03-27 16:20:32.051963 INFO TId    1640 CoreAutoDiscovery> 27/03/2019 16:20:32: Bulk Ping; Group ID: 5365; FOUND: 0Devices

2019-03-27 16:20:45.051977 INFO TId    1640 CoreAutoDiscovery> 27/03/2019 16:20:45: Bulk Ping; Group ID: 5365; FOUND: 0Devices

2019-03-27 16:20:58.130138 INFO TId    1640 CoreAutoDiscovery> 27/03/2019 16:20:58: Bulk Ping; Group ID: 5365; FOUND: 0Devices

2019-03-27 16:21:11.114526 INFO TId    1640 CoreAutoDiscovery> 27/03/2019 16:21:11: Bulk Ping; Group ID: 5365; FOUND: 0Devices

2019-03-27 16:21:24.536443 INFO TId    1640 CoreAutoDiscovery> 27/03/2019 16:21:24: Bulk Ping; Group ID: 5365; FOUND: 0Devices

2019-03-27 16:21:37.052077 INFO TId    1640 CoreAutoDiscovery> 27/03/2019 16:21:37: Bulk Ping; Group ID: 5365; FOUND: 0Devices

2019-03-27 16:21:50.067739 INFO TId    1640 CoreAutoDiscovery> 27/03/2019 16:21:50: Bulk Ping; Group ID: 5365; FOUND: 0Devices

2019-03-27 16:22:03.130265 INFO TId    1640 CoreAutoDiscovery> 27/03/2019 16:22:03: Bulk Ping; Group ID: 5365; FOUND: 0Devices

2019-03-27 16:22:16.114667 INFO TId    1640 CoreAutoDiscovery> 27/03/2019 16:22:16: Bulk Ping; Group ID: 5365; FOUND: 0Devices

2019-03-27 16:22:29.114702 INFO TId    1640 CoreAutoDiscovery> 27/03/2019 16:22:29: Bulk Ping; Group ID: 5365; FOUND: 0Devices

2019-03-27 16:22:42.130347 INFO TId    1640 CoreAutoDiscovery> 27/03/2019 16:22:42: Bulk Ping; Group ID: 5365; FOUND: 0Devices

2019-03-27 16:22:55.536612 INFO TId    1640 CoreAutoDiscovery> 27/03/2019 16:22:55: Bulk Ping; Group ID: 5365; FOUND: 0Devices

Thanks


Mar, 2019 - Permalink

This is indeed going to take a while, 11 days to be precise, if my math adds up. How about a different approach. Use something like this instead, create working devices only and start an autodiscovery on them?

# add the new device to the group with the template
$Group = Get-Group -Id <id of group> 
# run Get-DeviceTemplate to get a list of templates
$Group | Add-Device -Name "$address" -Host "<a-test-server-that-is-pingable>" -Template "Generic Device (Ping Only)" -AutoDiscover

You could run the script every day via scheduled tasks instead of using the auto discovery, which ...well...doesn't scale properly here :D

PRTGapi | Feature Requests | WMI Issues | SNMP Issues

Kind regards,
Stephan Linke, Tech Support Team


Mar, 2019 - Permalink