which type of encapsulation is required on your PE rout…

You are provisioning a new VPLS on your PE router. Your customer needs to send Q-in-Q traffic across the
VPLS.
In this scenario, which type of encapsulation is required on your PE router’s VPLS interface?

You are provisioning a new VPLS on your PE router. Your customer needs to send Q-in-Q traffic across the
VPLS.
In this scenario, which type of encapsulation is required on your PE router’s VPLS interface?

A.
ether-vpls-over-atm-llc

B.
extended-vlan-vpls

C.
vlan-vpls

D.
ethernet-vpls

Explanation:
The logical encapsulation vlan-vpls have the valid intefaces type of 802.1Q and Q-in-Q.
http://www.jnpr.net/techpubs/en_US/junos-space14.2/topics/concept/layer2-provisioning-overviewservice-attributes.html

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cyx

cyx

correct answer is B, extended-vlan-vpls.

https://www.juniper.net/documentation/en_US/junos/topics/usage-guidelines/vpls-configuring-interface-encapsulation.html

extended-vlan-vpls—Use extended virtual LAN (VLAN) VPLS encapsulation on Ethernet interfaces that have VLAN 802.1Q tagging and VPLS enabled and that must accept packets carrying TPIDs 0x8100, 0x9100, and 0x9901.
vlan-vpls—Use VLAN VPLS encapsulation on Ethernet interfaces with VLAN 802.1Q tagging and VPLS enabled. The PE router expects to receive Ethernet frames with VLAN tags that are service-delimiting. These VLAN tags can be used by the service provider to separate customer traffic. For example, LAN traffic from different customers can flow through the same service provider switch, which can then apply VLAN tags to distinguish one customer’s traffic from the others. The traffic can then be forwarded to the PE router.
Interfaces with VLAN VPLS encapsulation accept packets carrying standard TPID values only.

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fe

fe

B

Q-in-Q or formally known as IEEE 802.1ad

0x9100(non-standard QinQ ethertype)
Some vendors use the proprietary TPIDs 0x9100 and 0x9901 to encapsulate a VLAN-tagged packet into a VLAN-CCC tunnel to interconnect a geographically separated metro Ethernet network.

https://www.juniper.net/documentation/en_US/junos/topics/usage-guidelines/mpls-configuring-layer-2-switching-cross-connects-using-ccc.html

0x8100 VLAN-tagged frame (IEEE 802.1Q) & Shortest Path Bridging IEEE 802.1aq
0x88A8 Provider Bridging (IEEE 802.1ad) & Shortest Path Bridging IEEE 802.1aq

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Damir

Damir

Option B is correct:
PE(LDP VPLS) interface configuration:
flexible-vlan-tagging;
encapsulation extended-vlan-vpls;
unit 10 {
vlan-id 10;
}

CE interface configuration:
flexible-vlan-tagging;
encapsulation flexible-ethernet-services;
unit 10 {
vlan-tags outer 10 inner 20;
family inet {
address 192.168.254.1/24;
}
}

Works well.
Encapsulation “vlan-vpls” is limited:
root@PE# set interfaces ge-0/0/3 encapsulation vlan-vpls
root@PE# set interfaces ge-0/0/3 unit 10 encapsulation vlan-vpls

[edit]
root@PE# commit
[edit interfaces ge-0/0/3]
‘unit 10’
VPLS interfaces must have a VLAN-ID >= 512
error: configuration check-out failed

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