We have two EX4200 switches in the following configuration:

Router (.1)=====static route=====(.2) EX_01========trunk========EX_02

I want to configure a loopback or management interface on EX_02. Junos doesn't allow ethernet switching on a loopback address, only inet. Is there another way to set the loopback address on EX_02 so that it's routable back to EX_01?

I've read elsewhere that some people will just run a cable from the me0 port into an access port on the front of the switch. I may end up just doing that; seems unnecessary though.

  • Did any answer help you? If so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you could provide and accept your own answer.
    – Ron Maupin
    Feb 21 '18 at 18:26

If you are set on using a loopback address to manage the device, then you will need to add two IP addresses - one in-band l3-interface attached to the VLAN, and one on the loopback interface. Your upstream device will then need a route to the loopback with a next-hop of the in-band VLAN address.

Otherwise, just use an in-band address attached to a dedicated management VLAN trunked between your devices.

I'm not sure there is anything to be gained by plugging me0 around into the front ports.

  • "Your upstream device will then need a route to the loopback with a next-hop of the in-band VLAN address." I can just go test this out in a minute, but to clarify, you can set routes even though you're passing the traffic through a trunked port? Possible to give me an example?
    – Chris
    Dec 8 '17 at 0:48
  • EX_01 will need something like set routing-options static route <<EX_02 loopback>> next-hop <<EX_02 vlan.x address>> Dec 11 '17 at 7:39
  • The connection from EX_01 to EX_02 is a trunk port though...?
    – Chris
    Dec 11 '17 at 17:49
  • that doesn't matter - try the above Dec 12 '17 at 0:49

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