Configuration Guidelines For 10-Gigabit Ethernet Interfaces; Configuring Interface Speed And Duplex Mode - Cisco WS-C3750-48PS-S Software Configuration Manual

Configuring Ethernet Interfaces

Configuration Guidelines for 10-Gigabit Ethernet Interfaces

Follow these guidelines to avoid configuration problems:
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Configuring Interface Speed and Duplex Mode

Ethernet interfaces on the switch operate at 10, 100, or 1000 Mbps, or 10,000 Mbps and in either full-
or half-duplex mode. In full-duplex mode, two stations can send and receive traffic at the same time.
Normally, 10-Mbps ports operate in half-duplex mode, which means that stations can either receive or
send traffic.
Switch models include combinations of Fast Ethernet (10/100-Mbps) ports or Gigabit Ethernet
(10/100/1000-Mbps) ports, 10-Gigabit module ports, and small form-factor pluggable (SFP) module
slots supporting Gigabit SFP modules.
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Catalyst 3750 Switch Software Configuration Guide
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The speed and duplex features are not supported.
The 10-Gigabit interfaces do not support these QoS features:
– Policing
Auto-QoS for VoIP with Cisco IP Phones
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Servicing the egress queues by using shaped round robin (SRR) weights
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Limiting the bandwidth on an egress interface
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If a 10-Gigabit module port is configured as a SPAN or RSPAN destination port, its link rate
decreases.
Support for a cross-stack EtherChannel with up to two 10-Gigabit module ports.
You cannot configure speed or duplex mode on 10-Gigabit module ports; these ports operate only at
10,000 Mbps and in full duplex mode.
You can configure interface speed on Fast Ethernet (10/100-Mbps) and Gigabit Ethernet
(10/100/1000-Mbps) ports. You can configure duplex mode to full, half, or autonegotiate on Fast
Ethernet interfaces. You can configure Gigabit Ethernet ports to full-duplex mode or to
autonegotiate; you cannot configure half-duplex mode on Gigabit Ethernet ports.
You cannot configure speed on SFP module ports, but you can configure speed to not negotiate
(nonegotiate) if connected to a device that does not support autonegotiation. However, when a
1000BASE-T SFP module is in the SFP module port, you can configure speed as 10, 100, or 1000
Mbps, or auto.
You cannot configure duplex mode on SFP module ports unless a 1000BASE-T SFP module or a
100BASE-FX MMF SFP module is in the port. All other SFP modules operate only in full-duplex
mode.
When a 1000BASE-T SFP module is in the SFP module port, you can configure duplex mode
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to auto or full.
When a 100BASE-FX SFP module is in the SFP module port, you can configure duplex mode
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to half or full.
Half-duplex mode is supported on Gigabit Ethernet interfaces; however you cannot
Note
configure these interfaces to operate in half-duplex mode.
Chapter 11 Configuring Interface Characteristics
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