When configuring multiple sub interfaces on interface which is used as EVPN VXLAN underlay to establish VTEP tunnels, the traffic forwarding is affected.
Configuration example -
set interfaces et-0/0/1 flexible-vlan-tagging
set interfaces et-0/0/1 unit 1 vlan-id 500
set interfaces et-0/0/1 unit 1 family inet address 1.1.1.1/24
set interfaces et-0/0/1 unit 2 vlan-id 501
set interfaces et-0/0/1 unit 2 family inet address 1.1.1.2/24
Traffic loss as well as sometimes VTEP not coming up
This configuration is not supported in EVPN/VXLAN setups on QFX/EX platforms. The recommendation is to always use unit 0 as underlay interface to establish VTEP.
Example -
set interfaces et-0/0/1 unit 0 family inet address 1.1.1.1/24