Switching

This may be a newbie type question, but we are moving from EX 3300s to 3400s for our access switches in one of our buildings, and I was wondering about the prefferd way to stack (VC) these. The 3400s come with 2 40GbE QSFP+ ports in the back in addition to the 4 SFP+ ports up front.... so I was curious if there are advantages\disadvantages etc in using one or the other. Also, we don't have the switches in hand yet...do they ship with any "stacking cables" ??? 

Thanks all in advance ! 

https://www.juniper.net/assets/us/en/local/pdf/datasheets/1000581-en.pdf

Hi

I think you can use both the 40gig or 10gig interfaces as VC. The one advantage is the length of the cable that can be used for stacking

• The QSFP+ uplink ports on EX3400 and EX4300 switches, which support 40-Gbps speeds and can connect switches that are up to 492 feet (150 m) apart, are configured as VCPs by default, so you do not need to explicitly configure them.

• On all of these switches, the SFP+ uplink ports, which support 10-Gbps speeds and can connect switches that are up to 6.2 miles (10 km) apart, can be configured into VCPs.

As far as stacking cable is concerned i am not sure but they are not shipped with the switches itself.

Hope this helps

This is a really good document that I believe will clarify most of your questions as well it will show you best practices and configuration,

https://www.juniper.net/documentation/en_US/junos/topics/task/configuration/virtual-chassis-ex4300-configuring.html

- Question 1: QFSP+ vs SFP+

The simplest way to interconnect EX3400 or EX4300 switches into a non-mixed EX3400 or EX4300 Virtual Chassis is to install the switches within 492 feet of one another and interconnect them into a Virtual Chassis by using the QSFP+ ports. For an EX3400 or EX4300 Virtual Chassis, if the member switches must be installed in locations that are more than 492 feet apart (such as at a different site or at a distant location within the same site), or if you are using the QSFP+ ports for another purpose, or for any EX2300 Virtual Chassis, you must configure SFP+ uplink module ports into VCPs.

- Question 2: Stacking cables,

They do not come with them as they are not dedicated VC cables, they are just regular tranceivers, either QSFP+ or SFP+, below you can find a list of all supporetd tranceivers for EX3400 that you an use as reference,

https://apps.juniper.net/home/EX3400/Hardware%20Compatibility?prd=EX3400

Personally I would go with QFSP+ as you may need good bandwith between the members, also it is recommneded to use pre-provisioned style of config (although you have the 2 styles listed in the document).

I belive all this info should help you not only with your 2 questions but also with the config when the time comes, if you have any other quetions do not hesitate to let us know, if this solves your questions you can mark this as solution.

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@dtopojr wrote:

This may be a newbie type question, but we are moving from EX 3300s to 3400s for our access switches in one of our buildings, and I was wondering about the prefferd way to stack (VC) these. The 3400s come with 2 40GbE QSFP+ ports in the back in addition to the 4 SFP+ ports up front.... so I was curious if there are advantages\disadvantages etc in using one or the other. Also, we don't have the switches in hand yet...do they ship with any "stacking cables" ??? 

Thanks all in advance ! 

 

https://www.juniper.net/assets/us/en/local/pdf/datasheets/1000581-en.pdf

 

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I would suggest using the 40G ports on the back for two reasons

1. It gives you a high-speed 'back-plane' across your chassis

2. It leaves 10G ports available for you to uplink/downlink to other switches

Of course, it will depend on what you want to achieve.

Thanks to all that replied ! All replies were very helpful. I appreciate the super fast and concise information that I get here from the J-Net community! 

I am glad we were able to help!

Hi,
I want to stack Ex3400-24t and EX3400-48t and want to use QSFP ports. How  i need to connect ?

Thanks

Heda

Hi Hedayetul Islam,

use this link   https://www.juniper.net/documentation/us/en/hardware/ex3400/topics/topic-map/ex3400-virtual-chassis.html