Port Mtu Size; Administrative Status; Cisco Discovery Protocol; Port Channel - Cisco Nexus 1000V Configuration Manual

Port MTU Size

Port MTU Size
The maximum transmission unit (MTU) size specifies the maximum frame size that an Ethernet port can
process. For transmissions to occur between two ports, you must configure the same MTU size for both ports.
A port drops any frames that exceed its MTU size.
By default, the MTU size for each port is 1500 bytes, which is the IEEE 802.3 standard for Ethernet frames.
Larger MTU sizes are possible for more efficient processing of data with less overhead. The larger frames,
called jumbo frames, can be up to 9000 bytes in size, which is also the fixed system jumbo MTU size in the
Cisco Nexus 1000V.
For a Layer 2 port, you can configure an MTU size as the system default of 1500 bytes or the system default
jumbo MTU size of 9000 bytes.

Administrative Status

The administrative-status parameter determines whether an interface is up or down. When an interface is
administratively down, it is disabled and unable to transmit data. When an interface is administratively up, it
is enabled and able to transmit data.

Cisco Discovery Protocol

The Cisco Discovery Protocol (CDP) is a Layer 2 protocol that enables two devices that run CDP to learn
about each other. You can use CDP to troubleshoot the network by displaying information about the neighboring
devices that are linked through each interface. By default, CDP is enabled.

Port Channel

A port channel is an aggregation of multiple physical interfaces that comprise a logical interface. You can
bundle up to eight individual interfaces into a port channel to provide increased bandwidth and redundancy.
Port channeling also load balances traffic across these physical interfaces. The port channel stays operational
if at least one physical interface within the port channel is operational.
Any configuration changes that you apply to the port channel are applied to each interface member of that
port channel.

Guidelines and Limitations

Interface parameters have the following configuration guidelines and limitations:
• You usually configure Ethernet port speed and duplex mode parameters to auto to allow negotiation of
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the speed and duplex modes between ports. If you decide to configure the port speed and duplex modes
manually for these ports, consider the following:
◦ If you set the Ethernet port speed to auto, the device automatically sets the duplex mode to auto.
◦ If you enter the no speed command, the device automatically sets both the speed and duplex
parameters to auto (the no speed command produces the same results as the speed auto command).
Configuring Interface Parameters