Layer 2 Port Encapsulation
My first (hopefully of many) technical blogs.
OK, so port encapsulation may not sound like an exciting topic to write a piece on, but I have answered many questions on this and think it’s worth writing an article on.
The SR-OS is very different to the Cisco OSs due to the the fact you must configure a port ethernet encapsulation before you can tie any services to the port.
On Cisco, you set the encapsulation directly under the sub-interface a la:
ipv4 address 10.0.0.20 255.255.255.0
encapsulation dot1q 1000
encapsulation dot1q 1000 second-dot1q 2000
So each sub-interface can be set to either dot1q or qinq.
But, on Alcatel-Lucent SR-OS products, the port encapsulation must first be configured before any SAPs (equivalent of sub-interfaces) can be created.
There are three port modes on SR-OS that can be selected:
Null mode refers simply to untagged packets. This is similar to