Multiple Subnets in a VLAN – Configuration Guide

subnetvlan

Is it advisable to have multiple subnets with in a VLAN? If at all ports assigned with differently subnetted addresses are used in a VLAN, will they be able to communicate?

Assume the different subnet IP addresses are on different devices.

Example: a switch with 10.0.1.0/24 is connected to a host port of 10.0.2.0/24, both the ports are a member of same VLAN, will they be able to communicate?

Best Answer

Hosts on different networks will be unable to communicate with IP, except through a router. Routers route between networks. A host sending packets to a network different than its own network will send to its configured gateway, which is on the same network as it is.

There are some corner cases where you would put different networks on the same VLAN, but this is certainly non-standard. If you do this for any reason, you must be sure to document it thoroughly.