Cisco Catalyst 6900 Series 4-port 40 Gigabit Ethernet Fiber Module can operate in a number of modes. Performance mode enables 80 Gigabit Ethernet performance by using two ports without oversubscription. In Oversubscribed mode, the module uses four ports with 2:1 oversubscription. Details are as follows:
● 40 Gigabit Ethernet Oversubscribed mode (default)
◦ Four 40 Gigabit Ethernet ports using CFP transceivers.
◦ Ports are numbered as interface FortyGigabitEthernetslot#/1-4 (Figure 1).
◦ The interface range command is allowed.
● 10 Gigabit Ethernet Oversubscribed mode
◦ 16 10 Gigabit Ethernet ports using FourX adapters.
◦ Each FourX adapter has 4 SFP+ transceivers.
◦ Ports will be numbered as interface TenGigabitEthernetslot#/5-20 (Figure 2).
◦ The interface range command is allowed.
● Mixed 10/40 Gigabit Ethernet mode
◦ One-half of the module uses two CFP transceivers for 2 x 40 Gigabit Ethernet ports, while the other half uses two FourX adapters for 8 x 10 Gigabit Ethernet ports.
◦ Depending on which side has the 40 Gigabit Ethernet ports, port numbering is as follows:
● 40 Gigabit Ethernet ports on left: Interface FortyGigabitEthernet slot#/1-2 and interface TenGigabitEthernetslot#/13-20.
● 40 Gigabit Ethernet ports on right: InterfaceTenGigabitEthernetslot#/5-12 and interface FortyGigabitEthernetslot#/3-4.
● Performance mode (Figure 3)
◦ Note that Oversubscribed mode is the default setting.
◦ In 40 Gigabit Ethernet Performance mode, ports 1 and 3 will be active.
◦ In 10 Gigabit Ethernet Performance mode, ports 5-8 and 13-16 will be active.
◦ The command-line interface (CLI) is required to change modes. Check release notes for details.
◦ The mode can be changed per port group.
