This article explains the existence of sxe-0/0/x interfaces on QFX10k series devices and why these interfaces are seen on QFX10002 but not in the QFX10008 platform.
When we check the interfaces in the QFX10002 platform, we may find some sxe-0/0/x interfaces, which are shown to be up.
root@QFX10002> show chassis hardware
Hardware inventory:
Item Version Part number Serial number Description
Chassis EB272 QFX10002-36Q
Pseudo CB 0
Routing Engine 0 BUILTIN BUILTIN RE-QFX10002-36Q
FPC 0 REV 06 750-092102 BCBC3380 QFX10002-36Q
<snip>
root@QFX10002> show interfaces terse | match sxe
sxe-0/0/0 up up
sxe-0/0/1 up up
sxe-0/0/2 up up
These interfaces are not found in the QFX10008 platform.
root@QFX10008> show chassis hardware
Hardware inventory:
Item Version Part number Serial number Description
Chassis EC706 QFX10008
Midplane REV 10 750-095179 BCAS2807 QFX10008 Midplane
Routing Engine 0 BUILTIN BUILTIN RE-QFX10008
Routing Engine 1 BUILTIN BUILTIN RE-QFX10008
<snip>
root@QFX10008> show interfaces terse | match sxe
The sxe-0/0/x interfaces are the 10G interfaces, which connect to the BRCM CPE (internal) switch, which in turn connects to the CPU.
Originally the PE chip supports both 10GE and PCIe interfaces for local CPU connection.
But even though QFX10k and PTX share the same PE chips, they use the control plane differently.
In QFX10002 platform, sxe-0/0/x is 10GE interface for local CPU connection of each PE chip.