Ethernet Switching
Ethernet Switching

Cascading EX4200

‎06-23-2015 08:21 AM

Hi all,


My comany has a client who is moving personnel in their current building. We will be doing a server move, but obvious first priority is getting network access to those moving to a new (previously unpopulated) floor.


Our current set up has backbone servers and core switches (EX-4550) on one floor, with 2x10Gb aggregated fiber links running to access-level switches (EX-4200). The servers and just about everything else will be moving eventually, but in the mean time, my plan is to cascade service from one floor to another using the EX-4200 access switches to avoid the cost of additional fiber runs that won't be used in a month.


I've already broken on of the aggregate links to free up an active 10xGb port on the Ex-4200, my question is: is there any special configuration I need to do? I would like all traffic that enters the current switch (switch A) to follow its normal route abck to the servers, but also be reflected in the new link to the new switch (switch B). Is port mirroring the best way to do this? Are there other things I should be aware of?


(Yes, I know this is not ideal, I am limiting bandwidth and creating additional points of failure... bad bad bad. This si a temporary set up until the vendor hardware and building are fully run for our final set up)

Ethernet Switching
Accepted by topic author agentroadkill
‎08-26-2015 01:27 AM

Re: Cascading EX4200

‎06-23-2015 10:31 AM



You can just build an vlan trunk between the 4200 and the 4550 add the right ports in the 4200 in the right vlan if your are using multiple vlans and you are done.


Nothing will change then and everything will be reachable, port mirroring is not a solution for this. you use that when you want to monitor the traffic comming from a port or vlan for debugging perpose or some kind of sniffing


Please Mark My Solution Accepted if it Helped, Kudos are Appreciated Too
Ethernet Switching

Re: Cascading EX4200

‎06-26-2015 06:24 AM



Thanks for your help. I was nervous there would be some necessary port config horror.


For anyone else looking to do this, I found the easiest way was to use Juniper EZSetup to get the switch pre-configured, then connect to the network. After than DNS servers and set search paths etc. Using the CLI editor in the web interface seems to be easiest, as it offers the most straigh-froward commit/rollback options and exposes all the functionality of the switch.