Troubleshooting
Problem
In large cluster 1000+ hosts, head lim would not be able to process all the lim requests from compute host. Therefore lim becomes unresponsive and kernel will log the following message below.
kernel: possible SYN flooding on port X.
kernel: possible SYN flooding on port X. Sending cookies.
kernel: Possible SYN flooding on port X. Check SNMP counters.
kernel: Possible SYN flooding on port X. Sending cookies. Check SNMP counters.
kernel: TCPv6: Possible SYN flooding on port X.
Symptom
- LIM is unresponsive
- Unable to failover
- SYN flooding message in /var/log/messages
Document Location
Worldwide
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Document Information
Modified date:
27 April 2021
UID
ibm15967933