Open Learning

I just finished Module 4 and had some questins regarding the interface configurations.

For command: 

set ge-0/0/3 unit 0 family inet address 172.20.66.1/30

Where do you get the "Unit 0" part? Is that just a made up number? Why do you need a Unit number?

Also, for:  

set ge-0/0/4 vlan-tagging
set se-0/0/4 unit 300 vlan-id 300 family inet address 172.18.1.2/30

Is that how you would set a vlan tag (like encapsulation dot1q vlan# for Cisco)? Also, again with the Unit number...

Hello Seeley4859, 

The unit number creates a logical interface on the physical port and is a required option. It's like a sub-interface. 

The statements below would configure the ge-0/0/4 interface's unit 300 logical interface as a layer 3 interface  with a vlan-id of 300 and IP address. 

set ge-0/0/4 vlan-tagging
set ge-0/0/4 unit 300 vlan-id 300
set ge-0/0/4 unit 300 family inet address 172.18.1.2/30

 You can also look at module 7 that gives some examples. 

Thanks for using the forum. We pay attention to it. 

Thank you! That clears it up somewhat for me. I just finished Module 7 and it did give an example, although it was very brief.

That does the vlan-tagging option do? Does that just tell the system that the interface is using a vlan?

Hello Seeley4859.

If you want to assign the logical interfaces to a VLAN you have to turn on vlan-tagging at the physical interface configuration level. The logical units can then be assigned a vlan-id. This allows one physical port to send and receive traffic for multiple VLANs using the VLAN tags on the logical interfaces as the differentiator. The technical term for doing this is called multiplexing. Traffic for different networks can share the same port or link. 

https://www.juniper.net/documentation/en_US/junos/topics/task/configuration/interfaces-binding-a-vlan-id-to-a-logical-interface.html

Thanks again Seeley4859 for participating in the forum. 

Gordon