Cisco 7301 Installation And Configuration Manual page 71

Chapter 3 Starting and Configuring the Router
Configuring the Interface Transmission and Speed Modes
After changing the media type, configure the speed and duplex transmission modes to appropriately
Step 1
match the new interface characteristics. Changing the speed and duplex of a Cisco 7301 router Gigabit
Ethernet interface is done using the speed and duplex interface commands.
Note
speed { 10 | 100 | 1000 | auto }
duplex { full | half | auto }
The following speed/duplex settings are supported:
Media Type
-------------------------------------------------------------
RJ45
GBIC(1)
-------------------------------------------------------------
a.
b.
When using the SFP GBIC media, there is also the additional negotiation auto command that is used to
enable the IEEE 802.1z Gigabit Ethernet (1000 Mbps) autonegotiation protocol.
To turn this autonegotiation feature off (it is on by default), issue the interface command no negotiation
Step 2
auto. This is useful for connecting to other Gigabit Ethernet equipment that does not support
IEEE 802.1z autonegotiation.
Note
The media-type gbic mode will always default to 1000-Mbps, full-duplex operation as this is the only
configuration that is supported in this mode. Any speed or duplex commands are ignored while using
this media-type mode, even if present in the configuration (for an example, see output from show
running-config).
Debugging
Cisco IOS provides two commands to provide information on your interfaces: show interface
GigabitEthernet 0/X (where X is 0, 1, or 2) and show controllers GigabitEthernet 0/X (where X is 0,
1, or 2).
The output of the show interface command is useful for determining the current operating mode of the
interface (speed/duplex/media-type) and the current interface statistics.
The output of the show controller command displays more information specific to the Cisco 7301 router
Gigabit Ethernet interface. For example, it shows the detected link status, speed, and duplex, and also
determines the current status of autonegotiation and the link partners' abilities (if it is an
autonegotiation-capable interface).
OL-5418-07
These commands are only applicable when using the RJ-45 media.
Speed
10, 100, 1000, auto
1000, auto(2)
If you are using the no negotion auto command, the speed and duplex should be set to a value other
than auto for correct operation.
The only available speed in this mode is 1000 Mbps; there is no difference whether 1000 or auto is
selected.
The negotiation auto feature is not supported when using the media type rj-45 and will be
ignored if implementation is attempted.
Duplex
full, half, auto
full, half, auto
Cisco 7301 Installation and Configuration Guide
Configuring a Cisco 7301 Router
3-15