Bug ID 1069373: zxfrd may unexpectedly terminate during zone transfer operations.

Last Modified: Aug 25, 2026

Affected Product(s):
BIG-IP DNS(all modules)

Known Affected Versions:
14.1.4.4, 14.1.4.5, 14.1.4.6, 14.1.5, 14.1.5.1, 14.1.5.2, 14.1.5.3, 14.1.5.4, 14.1.5.6, 15.0.0, 15.0.1, 15.0.1.1, 15.0.1.2, 15.0.1.3, 15.0.1.4, 15.1.0, 15.1.0.1, 15.1.0.2, 15.1.0.3, 15.1.0.4, 15.1.0.5, 15.1.1, 15.1.2, 15.1.2.1, 15.1.3, 15.1.3.1, 15.1.4, 15.1.4.1, 15.1.5, 15.1.5.1, 15.1.6, 15.1.6.1, 15.1.7, 15.1.8, 15.1.8.1, 15.1.8.2, 15.1.9, 15.1.9.1, 15.1.10, 15.1.10.2, 15.1.10.3, 15.1.10.4, 15.1.10.5, 15.1.10.6, 15.1.10.7, 15.1.10.8, 16.0.0, 16.0.0.1, 16.0.1, 16.0.1.1, 16.0.1.2, 16.1.0, 16.1.1, 16.1.2, 16.1.2.1, 16.1.2.2, 16.1.3, 16.1.3.1, 16.1.3.2, 16.1.3.3, 16.1.3.4, 16.1.3.5, 16.1.4, 16.1.4.1, 16.1.4.2, 16.1.4.3, 16.1.5, 16.1.5.1, 16.1.5.2, 16.1.6, 16.1.6.1, 17.0.0, 17.0.0.1, 17.0.0.2, 17.1.0, 17.1.0.1, 17.1.0.2, 17.1.0.3, 17.1.1, 17.1.1.1, 17.1.1.2, 17.1.1.3, 17.1.1.4, 17.1.2, 17.1.2.1, 17.1.2.2, 17.1.3, 17.1.3.1, 17.1.3.2

Fixed In:
21.1.0.1, 21.0.0.3, 17.5.1.8, 17.1.3.4

Opened: Dec 21, 2021

Severity: 2-Critical

Symptoms

The zxfrd daemon may crash with a segmentation fault during zone transfers.

Impact

Interruption of DNS zone transfers

Conditions

This issue may occur under the following conditions: DNS zone transfers (AXFR or IXFR) are in progress Multiple zone updates or NOTIFY events are processed concurrently Internal memory handling failure occurs in signal handler

Workaround

There is no direct workaround. However: The issue is extremely rare and not reproducible in controlled environments Services typically recover automatically after zxfrd restart

Fix Information

Added enhanced diagnostic logging for failure paths, which is written to STDERR. zxfrd should be run in the foreground and stderr output redirected to a file for troubleshooting.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips