after years away from JunOS, working with Foundry (now Brocade) routers, I find myself with a new Juniper MX10. All I want to do is create a simple VLAN such that two ports share one routing interface, which has one IP address. On a Brocade, this is quite simple:
vlan 200 name layer3
untagged ethe 1/3 to 1/4
router-interface ve 200
interface ve 200
ip address 192.168.1.1/24
On JunOS, I've been googling and reading documentation for days. There are very intricate VLAN options, but, I haven't found anything that drills down to the simple stuff.
Thanks for any help; I'd rather not start any routing loops.
Best Answer
The MX platform does not have the general concept of a "VLAN" that is present on the whole platform. The MX only "sees" VLAN tags on incoming packets and can then act on these tags. What you want is to bridge packets from two ports that have the same VLAN-ID in the L2 header and then add a L3 interface to that bridge.
On the MX platform you have two ways of configuring bridges. Service Provider Style and Enterprise Style. As I'm more familiar with the SP style I'll answer your question that way:
Juniper MX SP Style Bridging
First you configure your interfaces to accept packets with the right VLAN tags:
Then configure a bridge domain that bridges these two:
Now you have a bridged VLAN 200 on these two ports.
Untagged / Access Interfaces
If you have an untagged "access" port that you want to bridge, you can do that too by using this syntax:
Then use
ge-0/0/0.0
in your bridge configuration.L3 Interface / Routing Interface
To add a L3 interface to the mix, first define an Integrated Routing and Bridging Interface (IRB) with your IP:
And then add this interface to your bridge:
That should complete your setup.
It's a bit more complex than the "normal" VLAN concept found on other switches/devices but it's also way more flexible. For example you could have another two ports that also have VLAN-ID 200 configured and they could have their own bridge, completely separated from the first bridge you just configured.
For a lot more information about the MX platform, including great examples, I recommend the MX Series book from O'Reilly/Douglas Hanks: http://shop.oreilly.com/product/0636920023760.do