Description

This is a Port Mirror implementation across two Juniper EX9208 switches (Remote port mirror scenario)

Traffic from production VLANs on the source switch is mirrored into a dedicated remote monitoring VLAN (Vlan 100 )and transported via an aggregated trunk link (AE0) to a Destination-Switch for packet analysis.

On the Destination-Switch I have a packet capture device connected to port xe-0/0/0 capturing traffic on Vlan 100


The mirrored frames are not successfully egressing to the capture tool.



Symptoms

Configuration on the Source-Switch:

set forwarding-options analyzer Remote-Analyzer input ingress vlan vlan_50

set forwarding-options analyzer Remote-Analyzer input ingress vlan vlan_60

set forwarding-options analyzer Remote-Analyzer output vlan vlan_100

 

set interfaces ae0 unit 0 family ethernet-switching interface-mode trunk

set interfaces ae0 unit 0 family ethernet-switching vlan members all

 

Configuration on the Destination-Switch:

set forwarding-options analyzer Remote-Analyzer input ingress vlan vlan_100

set forwarding-options analyzer Remote-Analyzer output interface xe-0/0/0.0

 

set interfaces ae0 unit 0 family ethernet-switching interface-mode trunk

set interfaces ae0 unit 0 family ethernet-switching vlan members all

 

set interfaces xe-0/0/0 unit 0 family ethernet-switching interface-mode trunk

set interfaces xe-0/0/0 unit 0 family ethernet-switching vlan members vlan_100

 

 

.

Solution

Remove trunk and vlan configuration from the xe-0/0/0 interface.
Output interface should only be configured with "unit 0 family ethernet-switching"

 

 

#delete interfaces xe-0/0/0 unit 0 family ethernet-switching interface-mode trunk
#delete interfaces xe-0/0/0 unit 0 family ethernet-switching vlan members vlan_100

 

Instead do:
#set interfaces xe-0/0/0 unit 0 family ethernet-switching

 

.

Modification History

2026-04-29 : Article Created