The problem encountered in configuring the Trunk+Etherchannel group is that PC1 and PC2 are on different network segments, but I want PC1 to be able to successfully interconnect with PC2 (ping is successful), how should I configure it? I would really appreciate your help!
You need a router in between to act as gateway between the 2 subnets or you need to reconfigure the 2 devices so they are on the same subnet (/22 instead of /24 or similar change) and same VLAN.
Also you left VLAN 88 out of the allowed VLAN list so whatever is in that VLAN won't pass over the trunk.
