SRX

So let's say I have a brand new SRX -- and this SRX is connected to a switch, then the switch to a couple PC's in different subnets.

That interface that is going to the switch has multiple interfaces going out to the switch.

Example: ge-0/0/0.50 ge-0/0/0.100 ge-0/0/0.200

- Does my switch then need to have that interface configured as a trunk and allow VLAN's 50, 100, 200?

- Then the ports going to the respective devices should be access ports for the VLAN?

Basically I guess what I'm saying is does having the interface be ge-0/0/0.50 mean that the packet (or I guess layer 2 frame) that leaves that interface is going to be tagged as VLAN 50?

Yes, these sub-interfaces are indicating that the port is 802.1Q tagged interface.  You assign the same tags to the switch port interface to connect the vlans.

Also note that in Junos the sub-interface number is independent of the actual tag value so you need to set  tag.  Typically we do match them to keep things consistent but this is not required.

Alright, that's what I thought, I appreciate it.

I guess I've always taken layer 2 for granted -- it's always just kinda done its thing.