Alcatel-Lucent 6850-48 Network Guide

Configuring Ethernet Ports

Setting Ethernet Parameters for Non-Combo Ports

OmniSwitch AOS Release 6 Network Configuration Guide

page 1-19

To configure crossover settings on a single port, a range of ports, or an entire slot, use the

 command. If autonegotiation is disabled, auto MDIX, auto speed, and auto duplex 

are not accepted.

Setting the crossover configuration to auto will configure the interface or interfaces to automatically 
detect crossover settings. Setting crossover configuration to mdix will configure the interface or inter-
faces for MDIX (Media Dependent Interface with Crossover), which is the standard for hubs and switches. 
Setting crossover to mdi will configure the interface or interfaces for MDI (Media Dependent Interface), 
which is the standard for end stations.

To configure crossover settings on an entire switch, enter interfaces, followed by the slot number, cross-
over, and the desired setting. For example, to set the crossover configuration to auto on slot 2, enter:

-> interfaces 2 crossover auto

To configure crossover settings on a single port, enter interfaces, followed by the slot number, a slash (/), 
the port number, crossover, and the desired setting. For example, to set the crossover configuration to auto 
on port 3 on slot 2, enter:

-> interfaces 2/3 crossover auto

To configure crossover settings on a range of ports, enter interfaces, followed by the slot number, a slash 
(/), the first port number, a hyphen (-), the last port number, crossover, and the desired setting. For exam-
ple, to set the crossover configuration to auto on ports 1 through 3 on slot 2, enter:

-> interfaces 2/1-3 crossover auto

 command is used to configure end-to-end (E2E) flow control (pause) settings for 

non-combo ports that run in full duplex mode. Configuring flow control is done to specify whether or not 
an interface will transmit, honor, or both transmit and honor PAUSE frames. PAUSE frames are used to 
temporarily pause the flow of traffic between two connected devices to help prevent packet loss when traf-
fic congestion occurs between switches. 

Using the interfaces pause command alone is sufficient to configure E2E flow control on a 24-port 
OmniSwitch 6400, a 24-port OmniSwitch 6850 and an OmniSwitch 6855 running in standalone mode. 
However, if a switch is a 48-port switch running in standalone mode, then a flow control VLAN is 
required in addition to enabling flow control. This type of VLAN is configured using the 

 command. 

Although E2E flow control is only supported on standalone OmniSwitch 6400, OmniSwitch 6850, and 
OmniSwitch 6855 switches, it is possible to configure a stack of switches or a chassis-based switch to 
honor PAUSE frames only. This is also done with the interfaces pause command.

Note that if autonegotiation and flow control are both enabled for an interface, then autonegotiation deter-
mines how the interface will process PAUSE frames. See 

 for more information. If autonegotiation is disabled but flow control is enabled, then the config-

ured flow control settings apply.

By default, flow control is disabled. To configure flow control for one or more ports, use the interfaces 
pause command with one of the following parameters to specify how PAUSE frames are processed:

• tx—Transmit PAUSE frames to peer switches when traffic congestion occurs on the local interface. Do 

not honor PAUSE frames from peer switches.