ECS4660-28F_Management Guide-R03

C HAPTER 31 | Interface Commands
Interface Configuration
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COMMAND USAGE
This command allows you to disable a port due to abnormal behavior
(e.g., excessive collisions), and then re-enable it after the problem has
been resolved. You may also want to disable a port for security reasons.
EXAMPLE
The following example disables port 5.
Console(config)#interface ethernet 1/5
Console(config-if)#shutdown
Console(config-if)#
switchport mtu This command configures the maximum transfer unit (MTU) allowed for
layer 2 packets crossing a Gigabit or 10 Gigabit Ethernet port or trunk. Use
the no form to restore the default setting.
SYNTAX
switchport mtu size
no switchport mtu
size - Specifies the maximum transfer unit (or frame size) for a
Gigabit and 10 Gigabit Ethernet port or trunk. (Range: 1500-9216
bytes)
DEFAULT SETTING
1518 bytes
COMMAND MODE
Interface Configuration (Ethernet, Port Channel)
COMMAND USAGE
◆ Use the jumbo frame command to enable or disable jumbo frames for
all Gigabit and 10 Gigabit Ethernet ports. To set the MTU for a specific
interface, enable jumbo frames and use this command to specify the
required size of the MTU.
◆ The comparison of packet size against the configured port MTU
considers only the incoming packet size, and is not affected by the fact
that an ingress port is a tagged port or a QinQ ingress port. In other
words, any additional size (for example, a tagged field of 4 bytes added
by the chip) will not be considered when comparing the egress packet’s
size against the configured MTU.
◆ When pinging the switch from an external device, information added for
the Ethernet header can increase the packet size by at least 42 bytes
for an untagged packet, and 46 bytes for a tagged packet. If the
adjusted frame size exceeds the configured port MTU, the switch will
not respond to the ping message.