I am hoping to get a steer on ethertype handling on an interface configured with QinQ on C9500-24Y4C switches, where the config looks something like
interface TwentyFiveGigE1/0/1
no switchport
!
interface TwentyFiveGigE1/0/1.1003
encapsulation dot1Q 1003 second-dot1q 1101
ip address 172.16.3.1 255.255.255.0
!
interface TwentyFiveGigE1/0/1.1004
encapsulation dot1Q 1004 second-dot1q 1101
ip address 172.16.4.1 255.255.255.0
!
interface TwentyFiveGigE1/0/1.1005
encapsulation dot1Q 1005 second-dot1q 1101
ip address 172.16.5.1 255.255.255.0
I see no option in the 17.6.4 code on my devices to configure the Ethertype on the QinQ using "switchport dot1q ether type" or similar and so by default does the interface use 0x88a8 for QinQ outer VLAN or is it defaultig to 0x8100 for both VLANs ??
The config guide for later versions, example below, where configuring the ethertype is permitted, it specifically calls out Cat9500-X so do we know is the configurable ethertype only a Cat9500-X option, in which case there is no point in me upgrading my device s/w to enable this config-knob ??
https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst9500/software/release/17-11/configuration_guide/lyr2/b_1711_lyr2_9500_cg/configuring_ieee_802_1q_tunneling.html#custom-ethertype
