Bug ID 1708309: Dynconfd Crash With Invalid Ephemeral Pool Member

Last Modified: Jun 18, 2026

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

Known Affected Versions:
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, 16.1.0, 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, 17.5.0, 17.5.1, 17.5.1.2, 17.5.1.3, 17.5.1.4, 17.5.1.5, 17.5.1.6

Opened: Oct 23, 2024

Severity: 3-Major

Symptoms

If the BIG-IP configuration is corrupted such that an ephemeral pool member exists without a corresponding FQDN template pool member, ephemeral node, or FQDN template node, the dynconfd daemon may crash repeatedly

Impact

The dynconfd daemon is responsible for resolving Fully Qualified Domain Names (FQDNs) to IP addresses and creating ephemeral nodes and pool members with those addresses. If an issue arises, dynconfd will be unable to resolve FQDNs in any existing FQDN template nodes and pool members, preventing them from being linked to their corresponding IP addresses. This can lead to a shortage of available pool members to handle incoming traffic

Conditions

This issue arises only when the MCP database becomes corrupted, leading to the presence of an ephemeral pool member without a corresponding FQDN template pool member, ephemeral node, or FQDN template node. This situation creates an invalid configuration that cannot be created through user action and can only occur as a result of MCP database corruption. It is important to note that such corruption is extremely rare, and its cause remains unknown Adding known condition from 01180684 1. Single AS3 transaction that simultaneously deleted old FQDN template nodes AND created a new FQDN node — creating a window where ephemeral members existed without parent template nodes 2. Rapid DNS churn (Kubernetes rollout in progress, TTL 30s, 18 A records changing) — means many ephemeral pool members were in-flight in MCP at the time of the transaction 3. autopopulate + interval ttl on FQDN members — ensures dynconfd actively tracks and processes ephemeral membership in real-time, maximizing exposure to the race

Workaround

To address corruption in the MCP database, follow the steps outlined in F5 knowledge article K13030: Forcing the MCPD process to reload the BIG-IP configuration

Fix Information

None

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips