questions for encapsulation for logical tunnel interface

05.24.11   |  
‎05-24-2011 03:41 PM

hi all:


on mx series, i use layer-2 port-mirroring to capture data and it works well (sure there are few bugs but...)). though i can get the feature working yet i still have some questions regarding how it works in details. here is the configuration for logical tunnel interface and port mirroring:


user@host# show interfaces lt-10/3/10

unit 1025 {
    encapsulation ethernet-bridge;
    peer-unit 1026;
    family bridge {
        filter {
            output pmx_layer2_fanout;
unit 1026 {
    encapsulation ethernet;
    peer-unit 1025;


{master}[edit forwarding-options port-mirroring instance]
user@host# show
pmx {
    input {
        rate 1;
        run-length 1;
    family vpls {
        output {
            interface lt-10/3/10.1025;


those lt interfaces function like a pipe, i used lt interfaces to connect two logical routers withboth ends encapsulated in frame-relay and they work as designed, nothing unclear about that. but in this specific application, one end must be "encapsulation ethernet-bridge" and another end must be "encapsulation ethernet". 


question is:


1) what is "encapsulation ethernet"??? it seems to be only for lt interfaces,

2) under the lt-10/3/10.1025, why output filer? does that mean lt-10/3/10.1025 is egress end? then where is the "ingress end" for the virtual pipe? lt-10/3/10.1026? but lt-10/3/10.1026 is not used...


thanks in advance...