Conntrack WALinuxAgent enables connection tracking for a security feature. You may need to adjust Linux OS configuration to support a large number of connections. Check dmesg output if you suspect the limit has been reached. References https://learn.microsoft.com/en-us/azure/aks/custom-node-configuration (net.netfilter.nf_conntrack_max) https://github.com/Azure/WALinuxAgent/blob/28345a55f9b21dae89472111635fd6e41809d958/azurelinuxagent/common/utils/networkutil.py#L186-L189