Administrator Guide

NOTE: In the User-Configured Cascade Ports field, A (active) indicates that a C9010 port is up (no shutdown) and
configured as a cascade port; I (inactive) indicates that a port is down and configured as a cascade port.
Dell# show interface port-channel brief
Codes: L - LACP Port-channel
O - OpenFlow Controller Port-channel
A - Auto Port-channel
LAG Mode Status Uptime Ports
A 258 N/A up 14:45:26 Te 0/1,2 (up)
Port Extender Limit
You can connect a maximum of 80 PE units to the C9010 control bridge.
Dell EMC Networking OS enforces a hard-limit of a maximum of 4000 PEX ports to be configured on each CB. This port limit on each CB
applies to both PEX ports as well as uplink ports that are converted to access (PEX) ports.
The PEX port count could increment in the following scenarios:
• Provisioning of PE units in the local mode, where all the supported PEX ports on each PE are provisioned.
• Converting uplink ports to access (PEX) ports.
• Remote provisioning of PEs in a VLT dual homing setup. Dell EMC Networking OS recommends to perform PE provisioning for VLT
only in the batch mode.
• Converting uplink ports to access (PEX) ports in a VLT dual homing setup. Dell EMC Networking OS recommends to perform the
uplink port conversion in VLT dual homing setups only using the batch mode.
If the number of PEX ports that you are trying to provision exceeds the prescribed hard-limit (4000), the system logs the following syslog
message:
Maximum number of PE ports limit (4000) reached. Rejected PE:PE Id Unit:PE Unit Id
configuration!.
The system also stops the provisioning of the extra ports or conversion of the uplink ports that is causing the PEX port limit to exceed the
hard-limit.
VLT Dual Homing scenarios
In a VLT dual homing setup, if the same PE units (maximum of 80 PE units) are configured in both the VLT CB nodes before the VLT
pairing is up, the PEX port counts on both the modes is the same after the VLT pairing is up.
However, if separate PE units (maximum of 80 PE units) are configured in each VLT CB node before the VLT pairing is up, the PEs may
not get synchronized properly after the VLT pairs come up. This is an erroneous configuration that may cause the system to become
unstable. To indicate this error state, a port validation error (PVE) is included in the show pe command output.
If the remote PE sync from the primary VLT CB node results in the PEX port count to exceed the prescribed hard-limit (4000), all the PEs
in the secondary VLT CB node are shown to be in PVE state.
Also, the system logs the following syslog message:
Secondary unit is in error state as the maximum number of PE ports limit reached!. Correct
the configuration and re-establish VLT to recover the system!.
To recover the secondary VLT CB node, you must configure the same PE units (maximum of 80 PE units) in both the VLT CB nodes and
re-establish the VLT connection.
For more information on dual homing, see Dual Homing.
PE Selection Logic
After you provision port extenders and power them on, the PEs come online according to the selection logic in the scenarios described in
this section.
• You may provision cascade ports for different PEs but connect the cascade ports to the same PE. In this case, only the PE with
lowest PE ID comes online. In the following example, both cascade ports 1/0 and 1/12 are cabled to the same PE. However, port 1/0 is
Port Extenders (PEs)
667