
Chapter 11
| Interface Commands
Interface Configuration
– 397 –
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 or
10 Gigabit Ethernet port or trunk. (Range: 1500-12288 bytes)
Default Setting
1518 bytes
Command Mode
Interface Configuration (Ethernet, Port Channel)
Command Usage
◆
Use the
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.
◆
For other traffic types, calculation of overall frame size is basically the same,
including the additional header fields SA(6) + DA(6) + Type(2) + VLAN-Tag(4)
(for tagged packets, for untaqged packets, the 4-byte field will not be added by
switch), and the payload. This should all be less than the configured port MTU,
including the CRC at the end of the frame.
◆
For QinQ, the overall frame size is still calculated as described above, and does
not add the length of the second tag to the frame.
◆
The port MTU size can be displayed with the show
command.
Содержание ECS4120-28F
Страница 36: ...Contents 36...
Страница 38: ...Figures 38...
Страница 46: ...Section I Getting Started 46...
Страница 70: ...Chapter 1 Initial Switch Configuration Setting the System Clock 70...
Страница 86: ...Chapter 2 Using the Command Line Interface CLI Command Groups 86...
Страница 202: ...Chapter 5 SNMP Commands Additional Trap Commands 202...
Страница 210: ...Chapter 6 Remote Monitoring Commands 210...
Страница 216: ...Chapter 7 Flow Sampling Commands 216...
Страница 278: ...Chapter 8 Authentication Commands PPPoE Intermediate Agent 278...
Страница 360: ...Chapter 9 General Security Measures Port based Traffic Segmentation 360...
Страница 384: ...Chapter 10 Access Control Lists ACL Information 384...
Страница 424: ...Chapter 11 Interface Commands Power Savings 424...
Страница 446: ...Chapter 13 Power over Ethernet Commands 446...
Страница 456: ...Chapter 14 Port Mirroring Commands RSPAN Mirroring Commands 456...
Страница 488: ...Chapter 17 UniDirectional Link Detection Commands 488...
Страница 494: ...Chapter 18 Address Table Commands 494...
Страница 554: ...Chapter 20 ERPS Commands 554...
Страница 620: ...Chapter 22 Class of Service Commands Priority Commands Layer 3 and 4 620...
Страница 638: ...Chapter 23 Quality of Service Commands 638...
Страница 772: ...Chapter 25 LLDP Commands 772...
Страница 814: ...Chapter 26 CFM Commands Delay Measure Operations 814...
Страница 826: ...Chapter 27 OAM Commands 826 1 1 00 12 CF 6A 07 F6 000084 Enabled Disabled Enabled Disabled Console...
Страница 836: ...Chapter 28 Domain Name Service Commands 836...
Страница 848: ...Chapter 29 DHCP Commands DHCP Relay Option 82 848...
Страница 902: ...Section III Appendices 902...
Страница 916: ...Glossary 916...
Страница 926: ...CLI Commands 926...
Страница 937: ......
Страница 938: ...E092017 CS R02...