Last Modified: Oct 16, 2026
Affected Product(s):
BIG-IP DNS
Known Affected Versions:
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, 17.1.3.4, 17.1.3.5, 17.1.3.6
Opened: May 16, 2025 Severity: 3-Major
The zxfrd (zone transfer daemon) process may crash with a segmentation fault on encountering a SERVFAIL response from an upstream server during an attempt to synchronize DNS zones. Logs like the following may appear in /var/log/ltm: zxfrd[12345]: 0353140a:3: Transfer of zone <zone_name> failed with rcode (SERVFAIL). zxfrd[12345]: 0353141a:5: Failed to transfer zone <zone_name> from <server>, will attempt AXFR
- Momentary interruption to zone transfer while the crashed process restarts - DNS query processing should not be impacted
- One or more DNS zones configured on the BIG-IP system and set up to transfer from an upstream server through zxfrd - Wrong zone or server misconfigured so that it returns a SERVFAIL in response to a zone transfer attempt - This happens very rarely unless exact specific conditions which are indeterminate are met. Memory pressure might be a required condition for this to occur.
Workaround by changing the system configuration to use a reliable nameserver.
None