Here are two correct ways:
con LSP_DC_Link1{p in Ports, t in Transit, c in LSP, d in DC: c not in {'ZIMU','ONEY'}}:
ContainersfromPortstoLSPtoDC[p,t,c,d] <= BigM * IsLSPDC[c,d];
con LSP_DC_Link1{p in Ports, t in Transit, c in LSP diff {'ZIMU','ONEY'}, d in DC}:
ContainersfromPortstoLSPtoDC[p,t,c,d] <= BigM * IsLSPDC[c,d];