Vlan – Juniper EX incoming packets VLAN tagged

juniperjuniper-exjuniper-junosvlan

I'm trying to configure a Juniper EX4200 switch. Usually packets are statically forwarded to me, but this time they are VLAN tagged. Here is my configuration :

interfaces {
    ge-0/0/0 {
        unit 0 {
            family ethernet-switching;
        }
    }
    // ...
     ge-0/0/46 {
        unit 0 {
            family ethernet-switching;
        }
    }
    vlan {
        unit 0 {
            family inet {
                address // The /29 configured on the next switch.
            }
        }
        unit 100 {
            family inet {
                address // End user's IPs.
            }
        }
    }
}

routing-options {
    static {
        route 0.0.0.0/0 next-hop // Gateway of the /29 on the next switch.;
    }
}

vlans {
    TEST_VLAN {
        vlan-id 100;
        interface {
            ge-0/0/46.0;
        }
        l3-interface vlan.100;
    }
    default {
        l3-interface vlan.0;
    }
}

The uplink is connected to switch port 0 and the end user (downlink) connected to switch port 46. I can SSH into the switch, but cannot get end user's IP addresses to respond to ping. I feel like the fact that incoming packets are VLAN tagged is messing things up, but I'm not sure how to deal with this?

Best Answer

Might be quicker to start over here - the below configuration should clean out what you have and give you a good place to start (don't commit this until the end though):

delete interfaces ge-0/0/0
delete interfaces ge-0/0/46
delete interfaces vlan
delete vlans TEST_VLAN

Firstly, create the L3 interface that we'll bind to VLAN_TEST later:

set interfaces vlan.100 family inet address x.x.x.x/29

Next, create VLAN_TEST, assign it a vlan-id and bind the above l3-interface to it:

set vlans TEST_VLAN vlan-id 100
set vlans TEST_VLAN l3-interface vlan.100

Then you'll need to set ge-0/0/0 to be in trunk mode in order to accept and send tagged frames and then add VLAN_TEST (100) to it:

set interfaces ge-0/0/0 unit 0 family ethernet-switching port-mode trunk
set interfaces ge-0/0/0 unit 0 family ethernet-switching vlan members TEST_VLAN

Finally, you'll need to allow VLAN_TEST to send/receive untagged frames (the default) on ge-0/0/46:

set interfaces ge-0/0/46 unit 0 family ethernet-switching vlan members TEST_VLAN

I remember having a conversation years ago with some of the product team when they were designing the EX about how they should do port and VLAN assignment - whether they would allow you to assign ports to VLANs from the VLAN/Bridge-Domain stanza (which is how they did it on their existing products at the time), or from under the interface configuration, so that people familiar with IOS would find it familiar.

They decided to support both methods simultaneously, which has been the cause of much confusion ever since.

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