Bug ID 737332: It is possible for DNSX to serve partial zone information for a short period of time

Last Modified: Oct 24, 2019

Bug Tracker

Affected Product:  See more info
BIG-IP DNS(all modules)

Known Affected Versions:
12.1.0, 12.1.0 HF1, 12.1.0 HF2, 12.1.1, 12.1.1 HF1, 12.1.1 HF2, 12.1.2, 12.1.2 HF1, 12.1.2 HF2, 12.1.3, 12.1.3.1, 12.1.3.2, 12.1.3.3, 12.1.3.4, 12.1.3.5, 12.1.3.6, 12.1.3.7, 13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.0.1, 13.1.0, 13.1.0.1, 13.1.0.2, 13.1.0.3, 13.1.0.4, 13.1.0.5, 13.1.0.6, 13.1.0.7, 13.1.0.8, 13.1.1, 13.1.1.1, 13.1.1.2, 13.1.1.3, 13.1.1.4, 14.0.0, 14.0.0.1, 14.0.0.2, 14.0.0.3, 14.0.0.4, 14.0.0.5, 14.0.1, 14.0.1.1

Fixed In:
14.1.0, 13.1.1.5, 12.1.4

Opened: Jul 18, 2018
Severity: 3-Major

Symptoms

During zone transfers into DNS Express, partial zone data may be available until the transfer completes.

Impact

Partial zone data will be served, including possible NXDOMAIN or NODATA messages. This happens until zone1 finishes and saves to the database, at which time both zones' data will be complete and correct.

Conditions

-- Two zones being transferred during the same time period + zone1.example.net + zone2.example.net -- Transfer of zone1 has started, but not finished. -- zone2 starts a transfer and finishes before zone1 finishes, meaning that the database might be updated with all of the zone2 data, and only part of the zone1 data.

Workaround

The workaround is to limit the number of concurrent transfers to 1. However this severely limits the ability of DNS Express to update zones in a timely fashion if there are many zones and many updates.

Fix Information

All zone transfers are now staged until they are complete. The zone transfer data is then saved to the database. Only when the zone data has completed updating to the database will the data be available to queries.

Behavior Change