A second set of traffic selectors is negotiated between two peers using IKEv2. Which IKEv2 packet will contain details of the exchange?

IKEV2_IKE_SA_INIT is only the first exchange and is used to negotiate cryptographic algorithms, exchange nonces, and perform the initial Diffie-Hellman exchange to establish the IKE SA itself, not additional Child SAs.

IKEV2_INFORMATIONAL is used for out-of-band error notifications, deletion of SAs, and liveness checking - not for negotiating new traffic selectors or Child SAs.

The IKEV2_CREATE_CHILD_SA exchange is specifically designed to create additional Child SAs or rekey existing ones after the initial IKE_SA_INIT and IKE_AUTH exchanges are complete. When a second set of traffic selectors needs to be negotiated, this exchange carries the new traffic selector proposals, nonces, and optional Diffie-Hellman values between the two peers.

IKEV2_IKE_AUTH authenticates the peers and establishes only the first Child SA during the initial IKEv2 exchange, not subsequent Child SAs.