Is a bridge necessary or how is it done?
I work through the CLI interface.
There is VLAN "X" (with internet). You need to give the Internet to the newly created VLAN "Y". Layer 3 switch - managed by Huawei.
It is possible from the theory - what is needed for this, bridges, locks? You can link where to read. I look for it myself, but I get some arguments about mistakes, non-working situations or muddled manipulations.

  • You don't need any VLANs. You need a router, or gateway, and you need to configure it for DHCP and PAT. You simply plug the switches uplink, or any one of it's ports, into the router and you're done. Jun 20, 2022 at 18:58
  • @RonnieRoyston, Why did you decide that VLANs were not needed? It's a huge organization with layered access security. Video surveillance, telephony, sound testing, TV commentary, outputs for connecting incoming TV companies and the like. Not to mention smaller VLANs for the needs of some paid hardware and so on.
    – I_CaR
    Jun 22, 2022 at 15:46

2 Answers 2


A VLAN is (more or less) like a virtual switch - VLANs partition a physical switch (infrastructure) into multiple, distinct layer-2 broadcast domains.

To enable inter-VLAN communication you require a router or layer-3 switch. You need to connect each VLAN to the router either by using separate routed (L3) ports, or by using a shared VLAN trunk with virtual subinterfaces. On an L3 switch you use a switch virtual interface (SVI) to bind to each VLAN. Since an L3 switch cannot provide IPv4 Internet connectivity (lacking NAT/NAPT), you'd need an additional WAN router for that.

If you bridge VLANs, you connect them to a larger broadcast domain, defeating the main purpose of creating VLANs.

Please add your device details (models, configurations) to your question for further help. Note that consumer-grade devices are explicitly off-topic here (and often not VLAN-capable anyway).


Based on your question you have some kind of router (connecting you to the Internet) and L3 switch with VLAN X and this works. This mean that you router have route to the ISP, and your L3 switch have SVI (Svitch Virtual Interface - vlanif x) that acting as gateway address for your existing VLAN "X". There is another VLAN let say VLAN "A" (VLAN that connect L3 and Router (vlanif A)) and vlanif A IP address is from same subnet as router interface that is faceing your internal network. Your L3 switch have default route that is redirecting traffic to the router LAN interface. (now let se what you need to configure - I assume that you vendor is Huawei so configuration is related to that vendor)

  1. You need to create VLAN "Y" (replace Y with number)

[Switch] vlan batch Y

  1. Choose ports that you want to connect with that VLAN (gi 0/0/1 and gi 0/0/2)
[Switch] interface range gigabitethernet 0/0/1 to gigabitethernet 0/0/2
[Switch-port-group] port link-type access     //access == connecting end device
[Switch-port-group] port default vlan Y      //adding interfaces to vlan Y
[Switch-port-group] quit
  1. Create SVI for that VLAN Y
[Switch]interface vlanif Y
[Switch-VlanifY] ip address x.x.x.x  x  (example.  24 ... usually first address from range dedicated to this network segment)
[Switch-VlanifY] quit
  1. Create DHCP pool for hosts inside VLAN Y
[Switch] interface vlanif Y
[Switch-VlanifY] dhcp select interface
[Switch-VlanifY] dhcp server dns-list x.x.x.x (x.x.x.x should be your ISP DNS)
[Switch-Vlanif2] quit

If this is your equipment setup then the most probably router is doing NAT, and you need to connect to router and configure NAT to allow new subnet to be translated. router configuration add existing ACL lets assume number of ACL is 2001:

  1. Check to see all ACL created on router

[Router] display acl all

identify what ACL match existing VLAN X address range (let assume it s ACL 2001, and that this ACL have one codition with sequence number 5, then we will another condition with sequence 10)

  1. Add ACL condition in existing ACL 2001
[Router] acl number 2001
[Router-acl-basic-2001] rule 10 permit source 
[Router-acl-basic-2001] quit
[Router] interface gigabitethernet 0/0/2   //this interface, is the one that facing internet
[Router-GigabitEthernet0/0/2] nat outbound 2001
[Router-GigabitEthernet0/0/2] quit 

Hope this helped, This solution is related to HUAWEI router and L3 switch and if you have access to this devices.

  • Basically it is S5720-56C P.S. I have done the first four stages. Thank you, I will try with your instructions further.
    – I_CaR
    Jun 22, 2022 at 15:50
  • @I_CaR if this helped you, please accept my answer, best regards
    – explorer
    Jun 25, 2022 at 5:57

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