This document describes a behavior observed on HPE Juniper Networking EX Series 4400 where QSFP-100GBASE-DR optics do not bring up Virtual Chassis Ports (VCP) when operating in HiGig VC mode. It explains the limitation and how to restore VCP connectivity using the correct mode.

You install QSFP-100GBASE-DR optics on EX4400 VCP ports and attempt to form a Virtual Chassis, but the VC links remain down.

When you check the VCP status, the interfaces show as configured but not operational:

user@switch> show virtual-chassis vc-port

fpc0:

Interface  Type       Trunk Status    Speed    Neighbor

or               ID         (mbps)    ID Interface

PIC / Port

1/0     Configured     -1  Down     50000

1/1     Configured     -1  Down     50000

1/2     Configured     -1  Down     50000

1/3     Configured     -1  Down     50000

The optics are detected correctly in hardware:

user@switch> show chassis hardware

Hardware inventory:

Item       Version Part number Serial number   Description

Chassis                          EX4400-48MP

FPC 0      REV XX  XXXXX    XXXXX       EX4400-48MP

PIC 1     REV XX  XXXXX    XXXXX       2x100G QSFP28 VCP

Xcvr 0    REV XX  740-088322  XXXXX       QSFP-100GBASE-DR

Xcvr 1    REV XX  740-088322  XXXXX       QSFP-100GBASE-DR

Despite this, the Virtual Chassis does not form and no neighbors are detected.

This behavior is expected. QSFP-100GBASE-DR, FR, and LR optics on EX4400 PIC1 operate as single-lambda 100G interfaces and do not support HiGig VC mode when the ports are split into 2x50G logical links.

To resolve the issue, you need to move the Virtual Chassis configuration to HGOE mode so the optics operate as full 100G interfaces.

From the CLI, configure the Virtual Chassis mode as HGOE:

user@switch> request virtual-chassis mode hgoe

The system will indicate that a reboot is required. Proceed with the reboot to apply the change.

After the device comes back online, verify the VCP status:

user@switch> show virtual-chassis vc-port

fpc0:

Interface  Type       Trunk Status    Speed    Neighbor

or               ID         (mbps)    ID Interface

PIC / Port

1/0     Configured     X  Up      100000    1  vcp-255/1/0

1/1     Configured     X  Up      100000    1  vcp-255/1/1

fpc1:

Interface  Type       Trunk Status    Speed    Neighbor

or               ID         (mbps)    ID Interface

PIC / Port

1/0     Configured     X  Up      100000    0  vcp-255/1/0

1/1     Configured     X  Up      100000    0  vcp-255/1/1

Confirm that the Virtual Chassis is now formed successfully:

user@switch> show virtual-chassis status

Virtual Chassis Mode: Enabled

Member ID Status  Model     Role

0     Present ex4400-48mp  Master

1     Present ex4400-48mp  Backup

After switching to HGOE mode, the QSFP-100GBASE-DR optics operate at full 100G and the VCP links come up successfully.