Cisco 7604 Configuration Manual page 136

Configuring Optional Interface Features
Configuring a nondefault MTU size on a 10-Gigabit Ethernet port limits ingress and egress packets to
the global LAN port MTU size.
Configuring a nondefault MTU size on an Ethernet port limits routed traffic to the configured MTU size.
You can configure the MTU size on any Ethernet port.
Layer 3 Ethernet Ports
On a Layer 3 port, you can configure an MTU size on each Layer 3 Ethernet port that is different than
the global LAN port MTU size.
Traffic through a Layer 3 Ethernet LAN port that is configured with a nondefault MTU size is also
Note
subject to the global LAN port MTU size (see the
section on page
Layer 2 Ethernet Ports
On a Layer 2 port, you can only configure an MTU size that matches the global LAN port MTU size (see
the
VLAN Interfaces
You can configure a different MTU size on each Layer 3 VLAN interface. Configuring a nondefault
MTU size on a VLAN interface limits traffic to the nondefault MTU size. You can configure the MTU
size on VLAN interfaces to support jumbo frames.
Configuring MTU Sizes
These sections describe how to configure MTU sizes:
•
•
Configuring the MTU Size
To configure the MTU size, perform this task:
Command
Step 1
Router(config)# interface {{vlan vlan_ID } |
1
{{ type slot/port } | {port-channel
port_channel_number } slot/port }}
Step 2
Router(config-if)# mtu mtu_size
Router(config-if)# no mtu
Step 3
Router(config-if)# end
Step 4
Router# show running-config interface
[{gigabitethernet | tengigabitethernet}
slot/port ]
1. type = ethernet, fastethernet, gigabitethernet, tengigabitethernet, or ge-wan
When configuring the MTU size, note the following information:
Cisco 7600 Series Router Cisco IOS Software Configuration Guide, Release 12.2SX
9-12
9-13).
"Configuring the Global Egress LAN Port MTU Size" section on page
Configuring MTU Sizes, page 9-12
Configuring the Global Egress LAN Port MTU Size, page 9-13
"Configuring the Global Egress LAN Port MTU Size"
Purpose
Selects the interface to configure.
Configures the MTU size.
Reverts to the default MTU size (1500 bytes).
Exits configuration mode.
Displays the running configuration.
Chapter 9 Configuring Interfaces
9-13).
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