I have a C9500 setup as erspan-destination. I know it is receiving the traffic because as soon as I direct a erspan-source to it, the cpu process goes up. But the C9500 won't dump the traffic on to the destination port. I have a C9300 setup exactly the same and it works as a erspan-destination just fine. All switches are at the same firmware level of 17.12.04. Only difference is that on the C9300, IP ROUTING is off by default. On the C9500 I turned IP ROUTING off. It shouldn't affect the erspan capability. (note; I am using the C9500 for its VSS capability between two data centers)
C9500-DEST#sho run | sect monitor session
monitor session 3 type erspan-destination
destination interface Twe1/0/15
source
erspan-id 100
ip address 10.10.10.20
C9300-DEST#sho run | sect monitor session
monitor session 3 type erspan-destination
destination interface Tw1/0/15
source
erspan-id 100
ip address 10.10.10.30
C9300-SOURCE#sho run | sect monitor session
monitor session 2 type erspan-source
source interface Gi1/0/1 - 48 rx
source interface Gi2/0/1 - 48 rx
destination
erspan-id 100
mtu 9000
ip address 10.10.10.20
origin ip address 10.10.10.40
C9500-DEST#show capability feature monitor erspan-destination
ERSPAN Destination Session:ERSPAN Destination Session Supported: TRUE
Maximum No of ERSPAN destination session: 8
ERSPAN Header Type supported: II and III
