TABLE OF CONTENTS
- Troubleshooting device connectivity with NMIS
- SNMP Troubleshooting
- SNMP v3 Troubleshooting
- Logs, debugs and files which are useful when troubleshooting and resolving issues in NMIS
- NMIS File Permissions
- Scaling NMIS Polling
- Scaling NMIS polling - how NMIS handles long running processes
- NMIS Showing Gaps in Graphs - Upgrade RRDTOOL
Devices Not Collecting / Device Information Not Displayed
Is the node reachable?
Ping it with a big echo request.
What does nmap think about it?
Node Not Present in GUI
Suddenly the node cannot be found in the GUI. When attempting to re-add the node to NMIS via the GUI we receive a 'node already exists' error.
Something has become very corrupt, we need to purge NMIS of all relevant node configuration.
- Open /usr/local/nmis8/conf/Nodes.nmis with an editor and delete the section for the problem node.
- Remove the following files:
- Re-add the problem node via the NMIS GUI
- Run the following commands:
The problem node should now be functioning properly in the NMIS GUI.
Manual Update & Collect Actions
If a node isn't providing the data we think it should sometimes looking at manual update & collect debugs is helpful. Redirect or tee the output to a file in order to review latter.
NMIS Tools and scripts
nmis.pl provides 2 methods for checking the directory structure of nmis and ensuring that the structure is complete and has the correct permissions (based on your Config.nmis). Running type=audit will report discrepancies between your structure and what is required, type=config will fix those errors
Additonally, the script fixperms.pl will go through and set the permissions on each file to ensure that NMIS can access the files it requires to operate normally
SELinux Troubleshooting Tip
Sometimes there are things happening on Linux systems which don't make sense, many times it is because SELinux is preventing things. You can spend a lot of time getting SELinux to behave, or you can put it in permissive mode, or disable it, in the NMIS VM it has been disabled.
Much information to be found with Google, the following describes either option.
Contacts.nmis must have the correct DutyTime format.
conf/Config.nmis must have the proper auth_method order as well as that method being provisioned.
If LDAP isnt working tcpdump can be used to see the response code from the LDAP server.
Long collect times
Are we collecting many interfaces that are not necessary?
Check the view.json file for number of interfaces and interface type. Look for common things such as interface type and description. Use models or Config.nmis to disable collection.
When troubleshooting syslog issues the following script will gather more rsyslog daemon information then the nmis support tool.
When troubleshooting snmptrapd issues the following script will gather more snmptrad daemon information then then nmis support tool.
When troubleshooting models it's important to know if all the OID's that have a 'friendly name' are referenced within Model files have been defined in /usr/local/nmis8/mibs/nmis_mibs.oid. Some Model files import or call other Model, Graph or Common files. If an OID 'friendly name' has not been defined in nmis_mibs.oid it may not be obvious which model file is causing the problem. In order to validate friendly names more easily the script below has been provided. It will parse all the OID friendly names out of the model files and look for them in nmis_mibs.oid. If they are not found the operator will be notified. At some point this script should be converted to perl; this would make it much faster.