HAIP Subnet Fliping Upon Link Down/Up Event

HAIP (High Availability IP) is Oracle’s private network redundancy feature in Grid Infrastructure. When a cluster has multiple private network interfaces, HAIP automatically bonds them, providing failover if one link goes down. Bug 29379299 reveals a critical flaw in how HAIP handles link recovery.

What happens:

1. Both private network links are UP. HAIP is healthy.
2. Link A goes DOWN. HAIP correctly fails over to Link B. All traffic continues on Link B.
3. Link A comes back UP.
4. Bug: Instead of staying on Link B (the current active link), HAIP “flips” — it attempts to reassign traffic to Link A, triggering a brief HAIP reconfiguration. During this reconfiguration, cluster interconnect traffic is interrupted, which can cause:
   • False node evictions (CSS thinks a node is dead due to missed heartbeats)
   • ORA-29740 (evicted by member) in database alert logs
   • Brief application outages even though both links are UP

Affected versions:

Oracle Grid Infrastructure 12.1.0.2 through 18c. Fixed in 19c starting with 19.4 RU.

Workarounds for older releases:

Option 1 — Disable HAIP and use OS-level bonding (bonding/teaming at the OS layer is more stable in most environments anyway):

# In GI home, set in crsconfig_params or run during install
-haip_no_config

Option 2 — Apply the one-off patch for Bug 29379299 (available for 12.1.0.2 and 12.2.0.1 through MOS).

Recommendation: If you’re on an affected version and your cluster has had mysterious node evictions following network maintenance or link flaps, check the CRS diagnostic logs ($GRID_HOME/log/<hostname>/cssd/ocssd.log) for HAIP reconfiguration events correlated with the eviction timestamps. This bug is the likely culprit.