service instance 100 ethernet | encapsulation untagged | bridge-domain 100

[Ibrahim Jamil]

Hi GUYS Pls find attachment why we need such Config , pls clarify thanks

[Hector Gustavo Serrano Gutierrez]

With the EVC feature, you can match 802.1q tags (or the lack of them) per interface and be routed in a bridge-domain.

You can configure 802.1q tags per interface and make that traffic take the appropriate routing.

This is an advantage over Global VLAN configurations. With it, the routing decision for 802.1q traffic receive is global to the system.

[Giuseppe Larosa]

Hello Ibrahim,

the interface is configured using EVC style of configuration.

Only untagged frames with no 802.1Q header are matched with

encapsulation untagged

the instance 100 accepts untagged frames and it is a member of bridge-domain 100.

Likely in bridge domain 100 configuration the L3 interface is declared to be SVI int vlan100.

The EVC style conforms to the metro ethernet forum specifications.

You can match a single 802.1Q tag or a range of 802.1Q vlan numbers up to 1-4094.

You can also match frames with double vlan tag and you can specify the outer vlan value or range and the inner vlan value or range.

This provides also for scalability.

To make an example for a customer we did the following:

a Hierarchical VPLS instance matching all tagged frames with vlan 1-4094 and with ethernet OAM on it.

using

enc dot1q 1-4094

a second Hierarchical VPLS using a second instance on same interface matching only untagged frames to allow plug and play service  without ethernet OAM support.

Hope to help

Giuseppe

[Ibrahim Jamil]

thanks guys