19
•
All interfaces on the device are operating in speed autonegotiation mode, with the highest
speed of 1000 Mbps.
•
Port D provides access to the Internet for the servers.
If the transmission rate of each server in the server cluster is 1000 Mbps, their total transmission rate
exceeds the capability of Port D.
To avoid congestion on Port D, configure 100 Mbps as the only option available for speed negotiation
on interfaces Port A, Port B, and Port C. As a result, the transmission rate on each interface
connected to a server is limited to 100 Mbps.
Configuration restrictions and guidelines
This feature is supported only on GE copper interfaces and copper ports of combo interfaces.
The
speed
and
speed
auto
commands supersede each other, and whichever is configured last
takes effect.
Configuration procedure
To set speed options for autonegotiation on an Ethernet interface:
Step
Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter Ethernet interface
view.
interface interface-type
interface-number
N/A
3.
Set speed options for
autonegotiation.
speed auto { 10 | 100 | 1000 } *
No option is set for speed
autonegotiation.
Setting the MDIX mode of an Ethernet interface
A physical Ethernet interface has eight pins, each of which plays a dedicated role. For example, pins
1 and 2 transmit signals, and pins 3 and 6 receive signals. You can use both crossover and
straight-through Ethernet cables to connect copper Ethernet interfaces. To accommodate these
types of cables, a copper Ethernet interface can operate in one of the following Medium Dependent
Interface-Crossover (MDIX) modes:
•
MDIX mode
—Pins 1 and 2 are receive pins and pins 3 and 6 are transmit pins.
•
MDI mode
—Pins 1 and 2 are transmit pins and pins 3 and 6 are receive pins.
•
AutoMDIX mode
—The interface negotiates pin roles with its peer.
NOTE:
This feature does not take effect on pins 4, 5, 7, and 8 of physical Ethernet interfaces. Pins 4, 5, 7,
and 8 of interfaces operating at 1000 Mbps or higher rates receive and transmit signals.
To enable a copper Ethernet interface to communicate with its peer, set the MDIX mode of the
interface by following these guidelines:
•
Typically, set the MDIX mode of the interface to AutoMDIX. Set the MDIX mode of the interface
to MDI or MDIX only when the device cannot determine the cable type.
•
When a straight-through cable is used, configure the interface to operate in an MDIX mode
different than its peer.
•
When a crossover cable is used, perform one of the following tasks:
Configure the interface to operate in the same MDIX mode as its peer.
Configure either end to operate in AutoMDIX mode.
