Chapter1 Configuring Interfaces and Circuits
Configuring Interfaces
1-8
Cisco Content Services Switch Routing and Bridging Configuration Guide
OL-8241-02
To remove an interface description, enter:
(config-if[2/1])# no description
Configuring Interface Duplex and Speed
By default, the CSS Fast Ethernet interface and Gigabit Ethernet interface are
configured to auto-negotiate. The CSS automatically detects the network line
speed (Fast Ethernet only) and duplex of incoming signals, and synchronizes
those parameters during data transfer. Auto-negotiation enables the CSS and the
other devices on the link to achieve the maximum common level of operation.
Note The CSS 1000BASE-T Gigabit Ethernet port supports 1000 Mbps full-duplex
operation only and does not support auto-negotiation.
When using Fast Ethernet ports with older equipment that cannot transmit the
duplex and speed with the signals, you can manually configure the speed
(10 Mbps, 100 Mbps) and duplex (half or full duplex) of the CSS port to match
the transmitting equipment.
When you use Gigabit Ethernet ports, if the link does not come up (perhaps due
to traffic congestion), you may need to force the CSS and its link partner in to a
specific mode. The CSS allows you to manually select a full duplex and flow
control (pause frame) mode. Flow control allows the CSS to control traffic during
congestion by notifying the other port to stop transmitting until the congestion
clears. When the other device receives the pause frame, it temporarily stops
transmitting data packets. When the CSS detects local congestion and becomes
overwhelmed with data, the Gigabit Ethernet ports transmits a pause frame. Both
the CSS Gigabit Ethernet and its link partner must be configured with the same
pause method (asymmetric, symmetric, or both). By default, all Gigabit Ethernet
ports are configured to full duplex mode with symmetric pause (pause frames
transmitted and received by the CSS).