Support Central: KB #5039: ‘set holddown’ command blocking all recursive queries
Problem Summary
The 'set holddown' command blocking all recursive queries
Customer Environment
Infoblox Grid running DNS service with global forwarders and 'set holddown' and forward-only clause enabled
Versions
All versions of NIOS
Cause
The 'set holddown' command cannot distinguish between a server or a forwarder and for this reason, all configurations are treated the same. Hence, all recursive queries may get 'held down'
Resolution
Disable the 'set holddown' command and instead use 'fetches-per-server' and 'fetches-per-zone' commands.
The holddown feature (stop query to server with too many timeouts) does not take forwarders into account. It should not be enabled on a server using forward only. The fetches-per-server feature (limit queries in-flight to any given server) does take forwarders into account. However, if you have a global forwarder then it makes no sense at all to enable the feature.
