Administrator Guide

Cabling Stacked Switches
Before you congure MXL switches in a stack, connect the 40G direct attach or QSFP cables and transceivers to connect 40GbE
ports on switches in the same or dierent chassis.
Cabling Restrictions
The following restrictions apply when setting up a stack of MXL 10/40GbE switches.
• Only daisy-chain or ring topologies are supported; star and full mesh topologies are not supported.
• Stacking is supported only on 40GbE links by connecting 40GbE ports on the base module or a 2-Port QSFP+ module. Stacking
is not supported on 10GbE ports or 4x10GbE ports.
– To convert the 40GbE ports on the 2-Port QSFP+ module from their default 4x10GbE mode of operation to 40GbE mode,
refer to Converting 4x10GbE Ports to 40GbE for Stacking.
• Use only QSFP transceivers and QSFP or direct attach cables (purchased separately) to connect stacking ports.
Cabling Redundancy
Connect the units in a stack with two or more stacking cables to avoid a stacking port or cable failure. Removing one of the stacked
cables between two stacked units does not trigger a reset.
Cabling Procedure
The following cabling procedure uses the stacking topology shown earlier in this chapter.
Follow the same steps to cable switches in any of the stacking topologies shown in Supported Stacking Topologies.
1. Connect a 40GbE port on the rst switch to a 40GbE port on the second switch.
2. Connect another 40GbE port on the second switch to a 40GbE port on the third switch.
3. Connect another 40GbE port on the third switch to a 40GbE port on the fourth switch.
4. Connect another 40GbE port on the fourth switch to a 40GbE port on the rst switch.
The resulting ring topology allows the entire stack to function as a single switch with resilient fail-over capabilities. If you do not
connect the last switch to the rst switch (Step 4), the stack operates in a daisy chain topology with less resiliency. Any failure in a
non-edge stack unit causes a split stack.
Accessing the CLI
To congure a stack, you must access the stack master in one of the following ways.
• For remote out-of-band management (OOB), enter the OOB management interface IP address into a Telnet or secure shell
(SSH) client and log in to the switch using the user ID and password to access the CLI.
• For local management, use the attached console connection to the master switch to log in to the CLI. Console access to the
stack CLI is available on the master only.
• For remote in-band management from a network management station, enter the virtual local area network (VLAN) IP address of
the management port and log in to the switch to access the CLI.
Conguring and Bringing Up a Stack
After you attach the 40G QSFP or direct attach cables in a stack of MXL 10/40GbE Switches, to bring up the stack, follow these
steps.
NOTE: The procedure uses command examples for the stacking topology shown previously in this chapter.
1. Set up a connection to the CLI on an MXL 10/40GbE Switch as described in Accessing the CLI.
2. Log on to the CLI and enter Global Conguration mode.
Login: username
768
Stacking