Huawei switches are configured with LACP on ports directly connected to H3C, but LACP is not configured on H3C switches (default port configuration). Why both ends can form LACP link aggregation function, and can send traffic normally?

Onsite are using S5560X-54F-EI and inter-connected with Huawei switch.

On Huawei switch has LACP configured on ports which directly conned to H3C and no LACP configure on H3C switch (default port configuration).

They found both sides can form LACP link aggregation function and can send traffic as normal.

If the Huawei set the LLDP while there is not configuration on our device. The members of interface aggregation would be work as one selected one unselected. The traffic can be transferred while only selected port can work.