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  • 1.  Juniper EX4300-48P - can I use normal ethernet port (1-48) as uplink port?

    Posted 01-09-2026 07:22

    Hi! I have Juniper EX4300-48P WITHOUT uplink ports module. I also do NOT have the proper cable to connect  Virtual Chassis (VC) QSFP+ to RJ45 (copper) to use it as uplink port.  My question is - can I use normal ethernet port (1-48) as uplink? I would like for example to use ethernet port number 24 (edge) as an uplink port so I can connect the switch with other switch/router. Thanks!



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    bart bati
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  • 2.  RE: Juniper EX4300-48P - can I use normal ethernet port (1-48) as uplink port?

    Posted 01-09-2026 08:25

    Yes you can. You have to configure the port as a trunk and add the VLANs you want the uplink to use.



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    MICHAEL TUMA
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    Original Message


  • 3.  RE: Juniper EX4300-48P - can I use normal ethernet port (1-48) as uplink port?

    Posted 01-10-2026 18:06

    Thank you Michael! Can you share a code I need to put in CLI? I'm a beginner and need to set this up (connect it to the router) before I start to learn how to configure proper setup.



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    bart bati
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    Original Message


  • 4.  RE: Juniper EX4300-48P - can I use normal ethernet port (1-48) as uplink port?
    Best Answer

    Posted 01-11-2026 21:11

    Hi Bart

    This is a config you could use

    Below set up port 24 as trunk

    You can replace with your own VLANs

    set interfaces ge-0/0/24 description "Uplink to router_switch"

    set interfaces ge-0/0/24 unit 0 family ethernet-switching interface-mode trunk

    set interfaces ge-0/0/24 unit 0 family ethernet-switching vlan members VLAN25

    set interfaces ge-0/0/24 unit 0 family ethernet-switching vlan members VLAN21

    set interfaces ge-0/0/24 unit 0 family ethernet-switching vlan members VLAN20

    set interfaces ge-0/0/24 unit 0 family ethernet-switching vlan members VLAN23

    set interfaces ge-0/0/24 unit 0 family ethernet-switching vlan members VLAN22

    set interfaces ge-0/0/24 unit 0 family ethernet-switching vlan members VLAN26

    set interfaces ge-0/0/24 unit 0 family ethernet-switching vlan members VLAN27

    set interfaces ge-0/0/24 unit 0 family ethernet-switching vlan members VLAN28

    your specific access ports would need mode "access" ( config not included here)

    Below you set up VLANs to be used in trunk, you can set management on some of those VLANs by using IRB interfaces if you want to do that, you can also use below 

    set vlans VLAN21 vlan-id 21

    set vlans VLAN28 vlan-id 28

    set vlans VLAN28 l3-interface irb.28

    set vlans VLAN20 vlan-id 20

    set vlans VLAN20 l3-interface irb.20

    set vlans VLAN22 vlan-id 22

    set vlans VLAN23 vlan-id 23

    set vlans VLAN23 l3-interface irb.23

    set vlans VLAN25 vlan-id 25

    set vlans VLAN25 l3-interface irb.25

    set vlans VLAN27 vlan-id 27

    set vlans VLAN27 l3-interface irb.27

    set vlans VLAN26 vlan-id 26

    set vlans VLAN26 l3-interface irb.26

    Below you set IRB interfaces for above VLANs 

    set interfaces irb unit 20 description VLAN20

    set interfaces irb unit 20 family inet address 192.168.20.2/24

    set interfaces irb unit 23 description Office_VLAN23

    set interfaces irb unit 23 family inet address 192.168.23.2/24

    set interfaces irb unit 25 description VLAN25

    set interfaces irb unit 25 family inet address 192.168.25.2/24

    set interfaces irb unit 26 description VLAN26

    set interfaces irb unit 26 family inet address 192.168.26.2/24

    set interfaces irb unit 27 description VLAN27

    set interfaces irb unit 27 family inet address 192.168.27.2/24

    set interfaces irb unit 28 description VLAN28

    set interfaces irb unit 28 family inet address 192.168.28.2/24


    Original Message


  • 5.  RE: Juniper EX4300-48P - can I use normal ethernet port (1-48) as uplink port?

    Posted 01-12-2026 09:40
    Edited by bart bati 03-18-2026 19:58

    @Rene11 Thanks!

    So just to be sure I set everything correctly when EX4300 arrive.

    First we set port 24 as a "trunk", so we add proper description and set it to trunk:

    set interfaces ge-0/0/24 description "UPLINK port to modem_router_switch"

    set interfaces ge-0/0/24 unit 0 family ethernet-switching interface-mode trunk

    Then our specific access ports would need mode "access", so it's something like:

    set interfaces ge-0/0/24 unit 0 family ethernet-switching mode access

    or something, right? Now we set names (members) of 8 VLANS (ports from 20 to 23 and from 25 to 28) to be "connect" (recognize) with our new UPLINK port number 24.

    set interfaces ge-0/0/24 unit 0 family ethernet-switching vlan members VLAN20

    set interfaces ge-0/0/24 unit 0 family ethernet-switching vlan members VLAN21

    set interfaces ge-0/0/24 unit 0 family ethernet-switching vlan members VLAN22

    set interfaces ge-0/0/24 unit 0 family ethernet-switching vlan members VLAN23

    --- (port 24 is UPLINK port)

    set interfaces ge-0/0/24 unit 0 family ethernet-switching vlan members VLAN25

    set interfaces ge-0/0/24 unit 0 family ethernet-switching vlan members VLAN26

    set interfaces ge-0/0/24 unit 0 family ethernet-switching vlan members VLAN27

    set interfaces ge-0/0/24 unit 0 family ethernet-switching vlan members VLAN28

    Now we setup those VLANS (give them proper ID's, and set interface as IRB - a virtual Layer 3 interface):

    set vlans VLAN20 vlan-id 20

    set vlans VLAN20 l3-interface irb.20

    set vlans VLAN21 vlan-id 21

    set vlans VLAN20 l3-interface irb.21

    set vlans VLAN22 vlan-id 22

    set vlans VLAN20 l3-interface irb.22

    set vlans VLAN23 vlan-id 23

    set vlans VLAN23 l3-interface irb.23

    set vlans VLAN25 vlan-id 25

    set vlans VLAN25 l3-interface irb.25

    set vlans VLAN26 vlan-id 26

    set vlans VLAN26 l3-interface irb.26

    set vlans VLAN27 vlan-id 27

    set vlans VLAN27 l3-interface irb.27

    set vlans VLAN28 vlan-id 28

    set vlans VLAN28 l3-interface irb.28

    Now we set IRB interfaces (logical units - proper IP addresses) for above VLANs :

    set interfaces irb unit 20 description VLAN20

    set interfaces irb unit 20 family inet address 192.168.20.2/24

    set interfaces irb unit 21 description VLAN21

    set interfaces irb unit 21 family inet address 192.168.21.2/24

    set interfaces irb unit 22 description VLAN22

    set interfaces irb unit 22 family inet address 192.168.22.2/24

    set interfaces irb unit 23 description Office_VLAN23

    set interfaces irb unit 23 family inet address 192.168.23.2/24

    set interfaces irb unit 25 description VLAN25

    set interfaces irb unit 25 family inet address 192.168.25.2/24

    set interfaces irb unit 26 description VLAN26

    set interfaces irb unit 26 family inet address 192.168.26.2/24

    set interfaces irb unit 27 description VLAN27

    set interfaces irb unit 27 family inet address 192.168.27.2/24

    set interfaces irb unit 28 description VLAN28

    set interfaces irb unit 28 family inet address 192.168.28.2/24

    So when we plug RJ45 (P8C8) to port 22 for example and we have setup IP of the plugged device as 192.168.22.X - it will be detected and work without a problem with our switch? Right?

    It is not tied to a specific port and we can use our UPLINK 24 port to connect different switch for example to access every VLAN we set up 192.168.20-28.X ?

    Thank you for clarify things I mess up here. Really appreciate your help.



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    bart bati
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    Original Message


  • 6.  RE: Juniper EX4300-48P - can I use normal ethernet port (1-48) as uplink port?

    Posted 01-12-2026 19:01

    That is right, on access ports you can set one VLAN as member, try one with IRB so you can ping EX4300 from laptop on IP .3 for example.

    i.e port 22 vlan 20,  port 23 vlan 24 etc

    then your trunk port 24 device , i.e router would have .1/24 IP you can then ping between that device and the ex4300 on IP .2

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    Original Message


  • 7.  RE: Juniper EX4300-48P - can I use normal ethernet port (1-48) as uplink port?

    Posted 03-19-2026 07:37
    Edited by Elevate 03-22-2026 07:39

    YES! My EX4300 finally arrived! Need to update it to newest version (mainly security reasons, cause config is the same) but about the configuration...

    ROUTER - IP 192.168.1.1

    SWITCH (EX-4300) - IP 192.168.2.2

    LAPTOP - IP 192.168.3.3

    so the TRUNK port on switch (ex-4300) is 24.

    Now for example I have 2 devices I need to connect to the router. At port 30 I have lets say camera, and at port 34 I have... printer!

    I configure port 30 (VLAN30, vlan-id 30, irb.30) by set it IP to 192.168.30.2

    and

    port 34 (VLAN34, vlan-id 34, irb.34) by set it IP to 192.168.34.2

    These ports would need to be in access mode:

    set interfaces ge-0/0/30 unit 0 family ethernet-switching interface-mode access (ONE vlan as a member so VLAN30)

    set interfaces ge-0/0/34 unit 0 family ethernet-switching interface-mode access (ONE vlan as a member so VLAN34)

    (TRUNK port [24] have those VLANs as its members, so it can 'see' [communicate with] them)

    So my router is connected to TRUNK (port 24) at EX-4300 switch and router can access camera (port 30) and printer (port 34) - also from the internet (with help of VPN for example), right?

    Now I want those devices to be available from my laptop.

    So I configure another port... let say port 32 as my laptop port (VLAN32, vlan-id 32, irb.32)

    set interfaces ge-0/0/32 unit 0 family ethernet-switching interface-mode access (ONE vlan as a member so VLAN32)

    And this port would need to have VLAN34 (port 34 - printer) as a member, to able to c0nnect with the printer, correct?

    So thanks to this config I can:

    ping 192.168.34.2 --- (port 34 - printer)

    from my laptop and get the response (cause VLANs get IRB - 'gateway' for VLANs to communicate means both Layer 2 bridging and Layer 3 routing on the same interface), right?

    So now when I try to connect to let say camera (port 30) at 192.168.30.2 I can do that from my laptop (if it has proper VLAN member), and with help of VPN from the internet (from any device like phone, tablet, etc.), right?

    And if I connect laptop to the TRUNK port (port 24) it will have access to the camera and printer immediately? So I can have (configure)  2 TRUNK ports, one for the router, and one for the laptop - to quickly connect the laptop (directly connect it to the EX-4300) switch and 'command&conquer' the equipmnet?

    Thanks for helping me out to proper understanding everything here.

    Those configurable switcher are amazing stuff, and now when many data centers replace old one with super-hiper fast new ones, the prices are fordable! The cost of full professional equipment is nearly the price of normal 10 port non-configurable switch from the shop! And I don't need 800Gb speed so if the nasty security bugs will be fixed in those junipers, they are simply great :)! Also community is great - a big + for noob like me ^^



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    bart bati
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    Original Message