Configuring Jumbo Frames enables the Ethernet interfaces to send and receive packets larger than the standard 1500 bytes. However, the actual transfer size depends on the switch capability and the device driver capability.
Note – Refer to the documentation that came with your switch for exact commands to configure Jumbo Frames support.
Enabling Jumbo Frames in a Solaris Environment
Now we will check how to enable Jumbo Frames in both a SPARC and an x86 environment.
- To Enable Jumbo Frames in a Solaris Environment Using nxge.conf
1. Enable Jumbo Frames for a port using the nxge.conf file.
name = "pciex108e,abcd" parent = "/pci@780/pci@0/pci@8/network@0" unit-address = "0" accept-jumbo=1;
2. Reboot the system:
# touch /reconfigure # init 6
# reboot -- -r
Tip*: reboot doesn’t call the stop scripts, it just send a kill un safe to the apps, be careful.
Note*: -r , it forces a hardware recheck
3. Set the maximum MTU for maximum performance:
# ifconfig nxge mtu 9194
procedure icon To Check Layer 2 Configuration
View the maximum transmission unit (MTU) configuration of an nxge instance at any time with the kstat command:
# kstat nxge:0 | grep mac_mtu
The kstat mac_mtu variable represents the complete size of the Ethernet frame, which includes the Ethernet header, maximum payload, and crc. The value of this variable should be equal to or less than the MTU configured on the switch.
- To Check Layer 3 Configuration
Check the Layer 3 configuration by using the dladm command with the show-link option.
# dladm show-link e1000g0 type: non-vlan mtu: 1500 device: e1000g0 e1000g1 type: non-vlan mtu: 1500 device: e1000g1 e1000g2 type: non-vlan mtu: 1500 device: e1000g2 e1000g3 type: non-vlan mtu: 1500 device: e1000g3 nxge0 type: non-vlan mtu: 9194 device: nxge0 nxge1 type: non-vlan mtu: 9194 device: nxge1 nxge38001 type: vlan 38 mtu: 9194 device: nxge1
Remember, Jumbo frames should be supported both by the ethernet card and the switch. Run these commands from the console, in case you will loose the conectivity due to a bad configuration, you can continue accesing the machine to restore a previous working one.