can 2 vlans have the same subnet? (2024)

FAQs

Can two VLANs have the same subnet? ›

the short answer is: no. each Vlan needs its own subnet.

Root Cause

When there are 2 interfaces on the same subnet there is no assurance as to which interface will be used to transmit traffic and the machine will accept traffic for either IP on either interface. This is because in Linux the IP address belongs to the host and is not associated with the interface.

Typically, in order for devices to be on the same subnet, the first three numbers of the IP address must match. The fourth number of the IP address must be different, as two devices cannot have the same IP address. For example, if your computer's IP address is 192.168. 0.1, then the subnet is 192.168.

VLANs can communicate with other VLANs when they both using the same trunk link to connect to the same layer 2 switch. 3. native VLAN can access other VLANs under the same layer 2 switch.

Yes if you separate a network with different VLANs you are creating separate networks like in subnetting. If you use VLAN to create different broadcast domain , subnetting becomes necessary as a part of it as you can not configure the two VLAN's with the same IP range.

A port can be a member of more than one VLAN of the same type if the device to which the port connects complies with the 802.1Q VLAN standard.

What happens when two devices on the same subnet are communicating? The host portion of the IP addresses will be different. The data link layer addresses are added to the IP header. The sending device will use ARP to determine the IP address of the receiver.

In short, yes! It is possible to use more than one router on the same home network, but you do need to be wary about the way you do this.

Absolutely! Explain the topology implemented in the two subnets to have a better idea on how the routing will be done. Bojan Zajc: Yes you can.

The figure also shows that a single host can also belong to more than one VLAN. For example, Host A has two VLANs configured over the host's interface. The second VLAN is configured with the VID 456 and is connected to Port 3 which is also configured with the VID 456.

Can you use the same IP address on different VLANs? ›

If multiple VLANs are configured, then each VLAN can have its own IP address. This is because each VLAN operates as a separate broadcast domain and requires a unique IP address and subnet mask. A default gateway (IP) address for the switch is optional, but recommended.

Yes, they can. The only thing you have to worry about is IP addressing. One or both domains will have to be statically IP addressed. The big thing would be moving from old DNS server to new DNS server.

In a properly designed IP network, a VLAN should map to a single broadcast domain, which should map to a unique IP network. For ease of troubleshooting (and for avoiding trouble!), traffic from one VLAN should not reach another VLAN without an OSI Layer 3 device, such as a router.

By default Vlans don't ping each other as they are designed to fragment and isolate devices within the network (this is the logic when working on vlans on layer 2). If you wish to have Vlans communicating with each other then this is accomplished at layer 3 via a router. The process is called inter-vlan routing.

For Inter-VLAN communication, a layer 3 device (usually a router) is needed. This layer 3 device needs to have an IP address in each subnet (VLAN) and have a connected route to each of those subnets. The hosts in each subnet can use the router's IP addresses as their default gateway.

The figure also shows that a single host can also belong to more than one VLAN. For example, Host A has two VLANs configured over the host's interface.

If multiple VLANs are configured, then each VLAN can have its own IP address. This is because each VLAN operates as a separate broadcast domain and requires a unique IP address and subnet mask. A default gateway (IP) address for the switch is optional, but recommended.

You will need to trunk the VLANs to the router and configure subinterfaces there for routing. You need to create encapsulation dot1q to perform router-on-stick or intervlan routing on your router. After that you can ping between different VLAN.