The QSFP+ or QSFP28 ports of the Extreme Networks switches can be partitioned, what this means is you can make a 40Gbit QSFP+ port appear as 4 x 10Gbit SFP+ ports, however you’re require a suitable QSFP+ module for example with MTP port and a fan-out cable to split that MTP into 4 x LC ports. Alternatively there are breakout panels that can provide the broken-out ports in a compact and easily manageable presentation.
You can breakout to Multi-Mode fibre only using the breakout panel, which means any QSFP 40Gbit Optics need to be multi-mode.
In this example port 97 is the number of a 40G port, its 3 sub-ports (10G) are 98,99 and 100. To configure as a 10G partitioned port, the following command is required:
configure ports 97 partition 4x10GYou’ll need to reboot the switch for this change to take effect.
What will now happen is you can use ports 97, 98, 99 and 100 as if they are individual 10Gbit SFP+ ports, yet they just back off into a single QSFP+ port.
Source: https://gtacknowledge.extremenetworks.com/articles/Q_A/Does-a-40G-port-support-4-x-10G-breakout-over-single-mode-fiber and http://documentation.extremenetworks.com/exos_commands/EXOS_21_1/EXOS_Commands_All/r_configure-ports-partition.shtml
