Bug ID 2182357: Inconsistent Default Source Address Selection for Virtual Server Between POST and PUT Requests

Last Modified: May 05, 2026

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

Fixed In:
17.5.1.6, 17.1.3.2

Opened: Dec 07, 2025

Severity: 3-Major

Symptoms

When a PUT request is made without specifying a source address, the system defaults to an IPv6 address (::). If the destination address is IPv4, this causes a validation error due to the mismatch between the source and destination address types.

Impact

The request fails with an address type mismatch error, requiring users to specify a compatible source address. This inconsistency between POST and PUT operations may cause confusion for users.

Conditions

A PUT request issued without a source address, having the destination address IPv4 The system attempts to apply a default IPv6 source address

Workaround

Explicitly specify a source address that matches the type (IPv4 or IPv6) of the destination address in the request payload.

Fix Information

The behavior of PUT requests has been updated to match that of POST requests. If a source address is not specified, the system now selects an appropriate default (IPv4 or IPv6) based on the destination address, ensuring consistency and avoiding address type mismatch errors.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips