jumbo frames

    to enable jumbo frames, use the ifconfig utility to increase the mtu beyond 1500 bytes.

    only enable jumbo frames if your network infrastructure supports them.

    the mtu range for jumbo frames is 1500 to 16114. for example, enter the following: ifconfig em[interface_num] mtu 9000

    vlans

    to enable vlans in the kernel, modify the config file as follows:

    pseudo-device vlan [num_vlans]

    then, recompile the kernel and reboot.

    to see the vlan device entries, use ifconfig.

    to attach a vlan to the driver enter the following:

    ifconfig vlan0 inet 10.0.0.1 netmask 255.255.255.0 vlan 1 vlandev em0 mtu 1500 up

    also, bring the driver up by entering:

    ifconfig em0 up