DELL MXL 10 User Manual

Stacking Dell Force10 MXL 10/40G Switches

Note: When creating stack ports on an MXL, all ports must be fixed or on the expansion module. Mixing
fixed and expansion module ports in order to stack is not supported.

Maximum stack-group per unit

A maximum of 4 stack-groups per unit can be configured. In a ring topology, that would be 2 stack-
groups in each direction, i.e 80Gbps stacking bandwidth. In a two unit stack, a maximum of 4 stack-
groups between the two units (i.e 160Gbps stacking bandwidth) is allowed. Trying to configure more
than 4 stack-groups results in the error shown here.

FTOS(conf)#do show system stack-unit 1 stack-group configured
Configured stack groups in stack-unit 1
------------------------------------------
0
1
2
3
FTOS(conf)#stack-unit 1 stack-group 4
% Error: Max stacking bandwidth for a unit is reached.

Cabling the stack

After setting these values save the configuration on each switch and reload each switch. Once all
switches to be used in the stack have reloaded, attach the stacking cables in a supported topology
using the MXL 40G-QSFP+ ports.   It is recommended to attach the Master and Standby (based on
priority or MAC address) first, then attach cables to the other members. As each cable is attached and
each unit joins the stack for the first time, notice that the first available Unit-ID (0-5) is assigned to
that unit, and the configuration for that unit is added into the running-configuration of the stack. Upon
subsequent reloads, the unit-ID is retained by each stack member.

If a new member with a higher Priority than the current Master joins the stack, it will become the
Master of that stack.  As cables are added and units join, the stack is dynamically built with the highest
priority switch becoming or staying the Master. The fastest and most efficient way to build the stack is
to connect the Master and Standby first so the stack will not go into a Master re-election when it finds
the higher Priority/MAC.

Validation

Issue the show system brief command to see the unit IDs present in the stack.

FTOS#show system brief
Stack MAC : 00:1e:c9:f1:00:7b
Reload Type : jump-start [Next boot : normal-reload]
--  Stack Info  --

Unit UnitType   Status      ReqTyp     CurTyp         Version    Ports
---------------------------------------------------------------------------------------------------
0 Management online    MXL-10/40GbE MXL-10/40GbE   8.3.16.0E0 56