Mac Address - Cisco 7301 Installation And Configuration Manual

Chapter 3 Starting and Configuring the Router
Hardware is BCM1250 Internal MAC, address is 0005.dd2c.7c19 (bia 0005.dd2c.7c19)
Internet address is 1.1.1.1/24
MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 1000Mb/s, link type is autonegotiation, media type is SX
output flow-control is off, input flow-control is off
ARP type:ARPA, ARP Timeout 04:00:00
Last input 00:04:42, output 00:00:01, output hang never
Last clearing of "show interface" counters 19:00:54
Input queue:0/75/22087/0 (size/max/drops/flushes); Total output drops:0
(display text omitted)
You can also use arguments such as the interface type (Ethernet, Token Ring, ATM, and so forth) and
the port address (slot-number/port-number) to display information about a specific interface only.
The following example shows the display for the first port on the Gigabit Ethernet port:
Router# show interfaces g0/0
GigabitEthernet0/0 is up, line protocol is up
Hardware is BCM1250 Internal MAC, address is 0005.dd2c.7c1b (bia 0005.dd2c.7c1b)
Internet address is 10.1.3.153/16
MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Half-duplex, 100Mb/s, media type is RJ45
output flow-control is off, input flow-control is off
ARP type:ARPA, ARP Timeout 04:00:00
Last input 00:00:00, output 00:00:01, output hang never
Last clearing of "show interface" counters 19:04:04
Input queue:0/75/63658/0 (size/max/drops/flushes); Total output drops:0
(display text omitted)
For complete descriptions and instructions of the commands used to configure your Cisco 7301 router,
refer to the Cisco IOS Configuration Fundamentals Configuration Guide and Cisco IOS Configuration
Fundamentals Command Reference publications at the following URL:
http://www.cisco.com/en/US/products/sw/iosswrel/tsd_products_support_category_home.html

MAC Address

All LAN interfaces (ports) require unique MAC addresses, also known as hardware addresses. Typically,
the MAC address of an interface is stored on a memory component that resides directly on the interface
circuitry; however, the OIR feature requires a different method. (For a description of OIR, see the
"Online Insertion and Removal" section on page
Using OIR, you can remove a port adapter and replace it with another identically configured one. If the
new port adapter matches the port adapter you removed, the system immediately brings it online. In order
to enable OIR, an address allocator with unique MAC addresses is stored in an EEPROM on the system
board. Each address is reserved for a specific port and slot in the router regardless of whether a port
adapter resides in that slot. The MAC address for the port adapter slot in the Cisco 7301 is slot 0. You
can remove a port adapter and insert it into another router without causing the MAC addresses to move
around the network or be assigned to multiple devices.
OL-5418-07
reliability 255/255, txload 1/255, rxload 5/255
reliability 255/255, txload 1/255, rxload 1/255
3-4.)
Cisco 7301 Installation and Configuration Guide
Functional Overview
3-3