I have a virtual chassis of 2 EX4600-40f. The 4 ports (0/0/1, 0/0/2, 0/0/3, 0/0/4) where my ESX are connected are configured in trunk mode with some vlans. I would like to copy the traffic (tagged) of my 4 ESX to a port (1/0/27) in order to analyze it.

I already configured an analyzer on the swtich :

input {
    ingress {
        interface xe-0/0/1.0;
        interface xe-0/0/2.0;
        interface xe-0/0/3.0;
        interface xe-0/0/4.0;
    egress {
        interface xe-0/0/1.0;
        interface xe-0/0/2.0;
        interface xe-0/0/3.0;
        interface xe-0/0/4.0;
output {
    interface xe-1/0/21.0;

ports to be mirrored config :

xe-0/0/2 {
    unit 0 {family ethernet-switching {
            interface-mode trunk;
            vlan {
                members [ 15 51 123 207 2260-2263 ];

port to connect the network analyzer :

xe-1/0/21 {
unit 0 {
    family ethernet-switching {
        interface-mode access;

But I have incorrect vlan tag on packet received by the server on the port 1/0/21, half of the traffic is tagged and the rest is not.

How can I do ? Is it possible to mirror a trunk port and keep tags?

Thanks in advance for your answers

  • Did any answer help you? If so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you could provide and accept your own answer. – Ron Maupin Aug 13 '17 at 20:19
  • Are you sure half the traffic is not tagged at all or have an incorrect tag? You may check the link below: juniper.net/documentation/en_US/junos/topics/task/configuration/… – Asif Oct 24 '19 at 4:48

Try to put interface xe-1/0/21 in trunk mode instead of access. I recall by experience on MX platform that I had to set a similar option on mirror port while doing layer2 mirroring for the packets to keep the tag. So maybe the same trick will do the job on EX. I didnt find documentation on this though.

| improve this answer | |
  • Your answer would be better if you expanded on it. – Ron Maupin Mar 26 '16 at 15:25

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