Bug ID 441048: IXFR falling back to AXFR may skew zone stats

Last Modified: Oct 06, 2020

Bug Tracker

Affected Product:  See more info
BIG-IP GTM, LTM(all modules)

Known Affected Versions:
11.2.0, 11.2.1, 11.3.0, 11.4.0, 11.4.1, 11.5.0

Fixed In:
11.6.0, 11.5.1, 11.5.0 HF1, 11.4.1 HF4, 11.2.1 HF11

Opened: Dec 17, 2013
Severity: 4-Minor
Related AskF5 Article:


It is permissible by the RFC for a DNS nameserver to return an AXFR response to an IXFR query. In this case, zxfrd (DNS Express), will properly handle the response. The actual zone data is also properly handled and not corrupted, however, the stats zxfrd keeps for the zone are not cleared and thus account for the AXFR plus the previous data. This is cosmetic. These skewed stats will be seen in all the UIs until the zone is reloaded, e.g. a zxfrd restart.


Stats misrepresent actual data in DNS-Express database. The database is consistent with the Primary nameserver so this stats data is cosmetic.


A DNS nameserver must respond with a full zone transfer when queried for an incremental zone transfer.


bigstart restart zxfrd.

Fix Information

The DNS Express Zone Resource Record counts now display accurate numbers when an AXFR answer is returned for an IXFR query.

Behavior Change