Which two channel group modes would place an interface in a negotiating state using pagp?

The two channel group modes that would place an interface in a negotiating state using Port Aggregation Protocol (PAgP) are "desirable" and "auto." When an interface is set to "desirable," it actively attempts to form a port channel by sending PAgP packets. In contrast, an interface configured in "auto" will only respond to PAgP packets from a "desirable" mode interface, leading to a negotiation state until a successful link aggregation is established.