Command to find out which ethernet card is connected to which Cisco switch port

show mac-address-table  | include b8ac.6f98

  10    b8ac.6f98.4cdf    DYNAMIC     Gi0/23
   1    b8ac.6f98.4cd7    DYNAMIC     Gi0/8
   1    b8ac.6f98.4cd9    DYNAMIC     Gi0/3

Where the above values are:

Vlan    Mac Address       Type        Ports
----    -----------       --------    -----

Note: You may have to ping the ip of the server NIC to get the MAC to appear in the switch mac-address-table

Use show mac-address-table and then narrow it down by piping the output to the include command restricted to part of the servers MAC  address

Display your server MAC addresses with:

 ifconfig -a | grep HWaddr
eth0      Link encap:Ethernet  HWaddr B8:AC:6F:98:4C:D7
eth1      Link encap:Ethernet  HWaddr B8:AC:6F:98:4C:D9
eth2      Link encap:Ethernet  HWaddr B8:AC:6F:98:4C:DB
eth3      Link encap:Ethernet  HWaddr B8:AC:6F:98:4C:DD