Brocade Communications Systems FastIron Administration Manual page 60

Maximum port speed advertisement and down-shift application notes
port to advertise a maximum speed of either 100 Mbps or 10 Mbps. When the maximum port speed
advertisement feature is configured on a port that is operating at 100 Mbps maximum speed, the port
will advertise 10/100 Mbps capability to the connected device. Similarly, if a port is configured at 10
Mbps maximum speed, the port will advertise 10 Mbps capability to the connected device.
The maximum port speed and down-shift advertisement features operate dynamically at the physical
link layer between two connected network devices. They examine the cabling conditions and the
physical capabilities of the remote link, then configure the speed of the link segment according to the
highest physical-layer technology that both devices can accommodate.
The maximum port speed and down-shift advertisement features operate independently of logical
trunk group configurations. Although Brocade recommends that you use the same cable types and
auto-negotiation configuration on all members of a trunk group, you could utilize the auto-negotiation
features conducive to your cabling environment. For example, in certain circumstances, you could
configure each port in a trunk group to have its own auto-negotiation maximum port speed
advertisement or port speed down-shift configuration.
Maximum port speed advertisement and down-shift application notes
• The maximum port speed advertisement works only when auto-negotiation is enabled (CLI
command speed-duplex auto ). If auto-negotiation is OFF, the device will reject the maximum port
speed advertisement configuration.
• When the maximum port speed advertisement is enabled on a port, the device will reject any
configuration attempts to set the port to a forced speed mode (100 Mbps or 1000 Mbps).
• When port speed down-shift or maximum port speed advertisement is enabled on a port, the device
will reject any configuration attempts to set the port to a forced speed mode (100 Mbps or 1000
Mbps).
Configuring maximum port speed advertisement
NOTE
This is not supported in ICX devices.
To configure a maximum port speed advertisement of 10 Mbps on a port that has auto-negotiation
enabled, enter a command such as the following at the Global CONFIG level of the CLI.
device(config)
# link-config gig copper autoneg-control 10m ethernet 1
To configure a maximum port speed advertisement of 100 Mbps on a port that has auto-negotiation
enabled, enter the following command at the Global CONFIG level of the CLI.
device(config)
# link-config gig copper autoneg-control 100m ethernet 2
Syntax: [no] link-config gig copperautoneg-control [ 10m | 100m ] ethernet port [ ethernet port ]
You can enable maximum port speed advertisement on one or two ports at a time.
To disable maximum port speed advertisement after it has been enabled, enter the no form of the
command.
60 FastIron Ethernet Switch Administration Guide
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