4-2
Ethernet Card Software Feature and Configuration Guide, R7.2
January 2009
Chapter 4 Configuring Interfaces
MAC Addresses
MAC Addresses
Every port or device that connects to an Ethernet network needs a MAC address. Other devices in the
network use MAC addresses to locate specific ports in the network and to create and update routing
tables and data structures.
To find MAC addresses for a device, use the show interfaces command, as follows:
Router# sh interfaces fastEthernet 0
FastEthernet0 is up, line protocol is up
Hardware is epif_port, address is 0005.9a39.6634 (bia 0005.9a39.6634)
MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, Auto Speed, 100BaseTX
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:01, output 00:00:18, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue :0/40 (size/max)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
11 packets input, 704 bytes
Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 11 multicast
0 input packets with dribble condition detected
3 packets output, 1056 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier
0 output buffer failures, 0 output buffers swapped out
Interface Port ID
The interface port ID designates the physical location of the interface within the ML-Series card. It is
the name that you use to identify the interface that you are configuring. The system software uses
interface port IDs to control activity within the ML-Series card and to display status information.
Interface port IDs are not used by other devices in the network; they are specific to the individual
ML-Series card and its internal components and software.
The ML100T-12 port IDs for the twelve Fast Ethernet interfaces are Fast Ethernet 0 thr ough 11. The
ML100X-8 port IDs for the eight Fast Ethernet interfaces are Fast Ethernet 0 through 7. The ML1000-2
port IDs for the two Gigabit Ethernet interfaces are Gigabit Ethernet 0 and 1. Both ML-Series cards
feature two POS ports, and the ML-Series card port IDs for the two POS interfaces are POS 0 and POS 1.
You can use user-defined abbreviations such as f0 to configure the Fast Ethernet interfaces, gi0 or gi1 to
configure the two Gigabit Ethernet interfaces, and POS0 and POS1 to configure t he two POS ports.
You can use Cisco IOS show commands to display information about any or all the interfaces of the
ML-Series card.
Caution Do not use the abbreviations g0 or g1 for Gigabit Ethe rnet user-defined abbreviations. This creates an
unsupported group asynchronous interface.