Core issue
The connectivity cannot be established when the switch is connected to the Ether Switch Module installed in a router through a straight through cable.
Resolution
Since both are switch ports, use a cross over cable in order to establish connectivity.
If you connect two Ether Switch Modules in the same chassis, you must connect them with the gigabit ethernet ports and a cross-over ethernet cable.
The Ether Switch Modules do not support Auto-MDI/MDIX detection. All the FE and GE ports are configured to be MDIX. Only the use of crossover cables is allowed when you connect to other MDIX ports and straight cables when you connect to MDI ports.
Device connected to switch
External router
