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Instead of using canned SSH-based probes for UNIX, we are researching the possibility of using SNMP against unix boxes (and possibly windows). In theory we can . We do this by simply replacing the SSH probes with equivalent SNMP probes which SNMP GET information from extended MIB objects which we apply to all machines we plan to instrument.
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...we may want to use SNMPv3, but the general idea is clear... we can expose arbitrary configuration data through SNMP. Since there are only a few dozen probes (and maybe only a subset of actual interest to Yale) we should be able to leverage SNMP for UNIX discovery instrumentation.
Rewire Discovery
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Rewiring of Discovery
- make sure SSH discovery doesn't happen
- no credentials
- configure the behavior of the MID server to skip SSH
- Expand the stock Linux classifier for SNMP so that it runs additional Explore-phase probes
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- replace the sensor
You can probably do this with XML field mapping as well, but here is a very simple scripted sensor that works from an SNMP probe payload:Code Block /* * bw - sensor for SNMP Distribution discovery (Yale SNMP Discovery) * * william.west@yale.edu */ new DiscoverySensor({ process: function() { // // XML should be in var payload (a global) var element = XMLUtil.getText(payload, '//unk_111'); var rows = element.split('\n'); //expecting multiple lines current.os = rows[0]; current.os_version = rows[1]; }, type: 'DiscoverySensor' }); - list the new sensor in the "Sensors" section of the appropriate probe record
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The most complete approach here is probably something like this:
- narrow down the sensors to those that apply to our asset types
- look at which ci_ tables are being edited by those and combine sensors with the same function
- generate a list of probes from those sensors
- generate a list of data needed by SNMP
- find out what standard MIBs provide the data
- generate a list of needed extensions for data not covered above