IP aliases randomly remain down while primary interface keeps working #1555
Description
Description
In rare and apparently random situations, IP aliases configured on an interface remain in a down state even though the primary interface continues to function normally.
When the issue occurs, the main interface (the one holding the primary IP address) keeps working correctly, but one or more configured IP aliases do not respond to traffic. The problem appears without any clear trigger and does not affect all aliases consistently.
Why / Purpose
IP aliases are commonly used for services, routing scenarios, or multi-IP setups. When an alias remains down while the main interface is still active, services bound to those IPs become unreachable even though the interface itself is operational.
This behavior may lead to unexpected service outages and can be difficult to detect because the interface appears healthy.
Proposed solution
Investigate the interface and alias management logic to verify whether there are conditions in which alias addresses are not correctly brought up or are left in an inconsistent state.
Potential areas to check include:
- interface reload or restart logic
- network reconfiguration events
- race conditions during alias initialization
- interaction with NetworkManager or underlying network scripts
References
NethSecurity 8.7.1