What Is a Conntrack Table?
The conntrack table is a kernel data structure that tracks the state of each active network connection so that NAT and stateful firewalls can match return traffic to the right flow. It has a maximum number of entries, and exhausting it causes new connections to be dropped. Service routing via iptables relies heavily on it.
Why it matters
A full conntrack table shows up as mysterious dropped connections under high load, common on busy CI nodes. Knowing it is finite explains those failures and why tuning its size helps.
Related guides
What Is kube-proxy Mode?kube-proxy mode is the mechanism kube-proxy uses to implement service routing on a node, such as iptables or…
What Is a Cluster IP?A cluster IP is a stable virtual address assigned to a service that is reachable only inside the cluster and…
What Is External Traffic Policy?External traffic policy controls whether inbound external traffic to a service is routed to pods on any node…