Last Modified: Sep 30, 2026
Affected Product(s):
BIG-IP DNS
Known Affected Versions:
17.1.3.5, 17.5.1.9, 21.1.0.2
Opened: Sep 22, 2026 Severity: 3-Major
When DNS Express is configured to store zone data using huge pages (via DNSExpress.HugePages), the zxfrd process cannot store updated zone data once the allocation of huge pages is exhausted. Additionally, there is no proactive SNMP or iHealth-based warning available before reaching this limit
DNS Express service disruption occurs when huge-page memory is exhausted, as zone transfers can no longer be stored. Recovery requires manual intervention (increasing DNSExpress.HugePages and restarting TMM), and users have no advance warning before the disruption occurs
DNSExpress.HugePages is configured with a non-zero value, and the size of the zone data (due to upstream zone growth, frequent updates, or fragmentation) approaches or exceeds the configured huge-page allocation
Size DNSExpress.HugePages conservatively, using the guidance in K54670218, and monitor /var/log/ltm for related messages at the info log level to detect early signs of huge-page pressure
None