connect cisco router with switch

i want to connect two servers through a dlink 1008v ethernet switch with cisco 7613 edge router. two ip addresses have been assigned to a single port on the router. when i connect a straight cable from the router with the server directly i am able to ping but when i am connecting a straight cable to the dlink switch from the router and another straight cable from switch to the server i am not able to ping fm the server, the lights on the switch however are up. is it a cable problem? somebody pse help