HP Cisco Catalyst Blade Switch 3020 Cisco Catalyst Blade Switch 3020 for HP Co - Page 545
system mtu, Cisco Catalyst Blade Switch for HP Command Reference, OL-8916-01,
View all HP Cisco Catalyst Blade Switch 3020 manuals
Add to My Manuals
Save this manual to your list of manuals |
Page 545 highlights
Chapter 2 Cisco Catalyst Blade Switch 3020 for HP Cisco IOS Commands system mtu system mtu Use the system mtu global configuration command to set the maximum packet size or maximum transmission unit (MTU) size for Gigabit Ethernet ports. Use the no form of this command to restore the global MTU value to its default value. system mtu {bytes | jumbo bytes} no system mtu Syntax Description bytes jumbo bytes The range is 1500 to 1998 bytes. This is the maximum MTU received at 10/100-Mbps Ethernet switch ports. Set the system jumbo MTU for Gigabit Ethernet ports operating at 1000 Mbps or greater. The range is 1500 to 9000 bytes. This is the maximum MTU received at the physical port for Gigabit Ethernet ports. Defaults The default MTU size for all ports is 1500 bytes. Command Modes Global configuration Command History Release 12.2(25)SEF Modification This command was introduced. Usage Guidelines When you use this command to change the system MTU or jumbo MTU size, you must reset the switch before the new configuration takes effect. Gigabit Ethernet ports operating at 1000 Mbps are not affected by the system mtu command, and 10/100-Mbps ports are not affected by the system mtu jumbo command. If you enter a value that is outside the range for the specific type of switch, the value is not accepted. Note The switch does not support setting the MTU on a per-interface basis. The size of frames that can be received by the switch CPU is limited to 1998 bytes, regardless of the value entered with the system mtu command. Although forwarded or routed frames are usually not received by the CPU, some packets (for example, control traffic, SNMP, Telnet, and routing protocols) are sent to the CPU. Because the switch does not fragment packets, it drops switched packets larger than the packet size supported on the egress interface. For example, if the system mtu value is 1998 bytes and the system mtu jumbo value is 5000 bytes, packets up to 5000 bytes can be received on interfaces operating at 1000 Mbps. However, although a packet larger than 1998 bytes can be received on an interface operating at 1000 Mbps, if its destination interface is operating at 10 or 100 Mbps, the packet is dropped. OL-8916-01 Cisco Catalyst Blade Switch for HP Command Reference 2-517