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#4035: Logs/data required to troubleshoot DHCP issues

Problem Summary

This KB will help in collecting logs/data required to troubleshoot different DHCP related issues.

 

Customer Environment:

Infoblox grid or standalone appliance running DHCP service.

 

Version:

All NIOS Version

DHCP server not leasing out IP Addresses

 

Please do the following if you are still experiencing the issue:

  • If you have a client which reported the issue, please do the following steps:
    • Start a Traffic capture on the Infoblox DHCP server (both peers if range is associated to DHCP Failover).
    • Reboot the client
    • Download the capture from the DHCP server (both peers if range is associated to a DHCP Failover)

Logs/data to be collected:

  • Support bundle from the DHCP server (from both peers if associated to DHCP failover).
  • Are you having issues with all networks or some specific network?
  • If the issue is with some specific network, then please provide the network having the issue
  • Was this configuration working before?
  • If it was working before, was there any network changes which could have caused this issue?
  • If range is assigned to a DHCP Failover association, what is the current status of the association?
  • MAC Address of the test client used in the above test.
  • Traffic captures taken in the above test.
  • CPU and process outputs for the below commands from the CLI of the DHCP server showing the issue: Please enter maintenance mode (by using command set maintenancemode) before using the below commands.
    • show cpu 1 10:  The "show cpu" command reports information about cpu activity.  The "1 10" option means run the command 10 times, pausing for 1 second between each execution.
    • show process all: The "show process" command shows information about the running processes on the appliance.  The "all" option reports all of the processes. The "set maintenancemode on" command enable other commands not normally available. Please use caution and only run these commands when instructed to do so for diagnostic purposes.
    • show memory: The show memory command reports on memory statistics (used, available, ...)
    • show capacity: The show capacity commands shows information about the database on the appliance, reporting a percentage of use compared to the maximum allowed size, as well as a breakdown by object type, giving a "big picture" of what is contained in the database on the member.

If you are currently not experiencing an issue, but looking for an RCA, please provide the below details:

  • Time frame in which the issue occured.
  • Support bundle from the DHCP server (both peers if range is associated to a DHCP Failover).
  • Did you face this issue on all networks or some specific network?
  • If the issue is with some specific network, then please provide the Network which had the issue.
  • Traffic capture (if taken) during the time of the issue.
  • MAC address of a client (if available) who reported the issue or used for testing when the above capture was taken.
  • CLI outputs as mentioned above during the time of the issue.
  • How was the issue resolved? Reboot/Restarted DHCP service?

 

Delay in DHCP OFFER/ACK

 

Logs/data to be collected:

  • Support bundle from the DHCP server (both peers if associated to DHCP failover)
  • If range is assigned to a DHCP Failover association, what is the status of the association?
  • Issue only for one network or multiple networks?
  • If the issue is with some specific network, then please provide the network having the issue.
  • Traffic capture (both peers if associated to DHCP Failover) taken on the DHCP server during the time of the issue.
  • CPU and process output (collect output of 3 iterations) for the below CLI commands from the DHCP server:

Infoblox > show connections numerical

Infoblox > show cpu 1 10

Infoblox > show memory

Infoblox > set maintenancemode

Maintenance Mode > show process all

Maintenance Mode > set maintenancemode off

  • Output of DDNS queue. Execute the following CLI command

show dhcp_dddns_updates

 

DHCP failover peer showing 'configuration file mismatch' message

 

Logs/data to be collected. Please take the below data during the time of the issue:

  • Support bundle from both servers in the DHCP failover association. 
  • Support bundle from the Grid Master.
  • Database backup from the Grid.

 

Use the instructions in the following KB articles to download a Support bundle and upload it to our secure FTP server.

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