I would like to create a l2circuit that I received a untagged frame from the customer and add a tag, because on the other side I will use a switch and share the same interface and my customer needs to know from what location came the packets, that's why I will use VLAN for differents location. I have a Juniper SRX240 and SRX340 and a 6730 huawei swtich. I send a topology image, I hope this helps.

enter image description here

How can I create a interface at Juniper? I tried use native-vlan-id, but i cant because i need to use ccc encapsulation. Is there another way?

  • 1
    Maybe restate or clarify what you want to achieve. It looks like you have a single network (Client XX) and you want to use VLAN tagging to identify the source of inbound traffic to the same network (Client XX) after it goes through one or another router. The VLAN tag will not persist through a router. You should clarify if you are talking about different locations and networks of the same organization (Client XX) or one location/network and why the routers are there (part of the solution?). With or without VLANs you always know where packets came from, it's the source address of a packet. Jul 11, 2023 at 18:57
  • I have the same client in different locations, my client is gonna send me untagged packets and router juniper (SRX) is part of solution, I need to delivery this packets at same interface at my switch huawei and my client needs to know what location send the packtes, thats why I need to use VLAN at switch huawei, but as my client is gonna send untagged packets I need to tag this packet.
    – Rafael
    Jul 11, 2023 at 19:33

1 Answer 1


This config works with martini-circuits on our MX204 Boxes, i never tried to configure L2 Services on a SRX. You have to do this that way to achieve a proper negotiation with the l2circuit peer.

interfaces {
        xe-0/1/5 {
                native-vlan-id 4000;
                encapsulation flexible-ethernet-services;
                unit 4000 {
                        encapsulation vlan-ccc;
                        vlan-id 4000;
  • Thanks for reply, but I tried this already and I got this error: admin@ROUTER-R3# show | compare [edit interfaces] + ge-0/0/2 { + flexible-vlan-tagging; + native-vlan-id 4000; + encapsulation flexible-ethernet-services; + unit 4000 { + encapsulation vlan-ccc; + vlan-id 4000; + } + } edit admin@ROUTER-R3# commit check [edit interfaces ge-0/0/2] 'flexible-vlan-tagging' Only compatible with vpls vlan encapsulations or no encapsulation error: configuration check-out failed: (statements constraint check failed)
    – Rafael
    Jul 11, 2023 at 19:39
  • Might be a restriction on the SRX Platform. If you google the error your "commit check" is thowing you'll find several (quite old) Postings of users that struggle on the same configuration. Some also had configs that worked on MXes but not on SRXes. I tried to find some infomation about restrictions on L2Circuits on SRXes but could't find anyting appropriate. I think the best way is to double-check with JTAC, if you have the appropriate service. Jul 12, 2023 at 21:02

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.