Does an EtherChannel perform checks on a new interface or an opposite switch even if it is enabled manually? E.g. not using LACP or PaGP. I would assume that it does but I couldn't find a clear answer.
Further to this, are all the checks performed on a new port being added (e.g. Speed, Duplex, Access/Trunk, VLANs, STP) also run between switches to ensure interfaces at each end of the channel match?