You are creating a Cilium network policy for pods with the label app: frontend .

Technical explanation

Option C has the correct Cilium policy structure. It selects pods labeled app: frontend , creates an egress rule with a valid CIDR entry, and combines that destination constraint with toPorts , port 8888 , and protocol TCP . Because the CIDR and port restriction are in the same egress rule, traffic must meet both conditions.

Option A uses an unsupported address-range structure with from and to fields rather than CIDR notation. Option B initially resembles the correct form but contains an additional malformed ports item at the egress-rule level. Option D uses unsupported action: allow and action: deny fields inside toPorts ; Cilium allow and deny behavior is expressed through policy sections such as egress and egressDeny , not per-port action properties.

The item is nevertheless defective. The prose and examples indicate 192.168.9.0/24 , while all displayed CIDR-based options specify 192.168.0.0/24 ; the source text itself shows the corrupted 192.168.e.e/24 . If 192.168.9.0/24 is authoritative, none of the exhibits permits the stated example. The supplied key B is structurally incorrect under the displayed manifests.

Official references

Cilium Layer 3 and CIDR Policies

Study Guide topic: CIDR selectors, Layer 4 ports, and rule composition.