vlan gatway in different switches

[Manish Manwal]

hi everyone,

we have 13 plant in different location, all plant is connected through fiber. every plant have a l3 switch in their gatway (cisco 3850, 3650, 2960-i). currently we use l2 technology to connect all plant. all plant have some same vlan, and gatway of all vlan's is configured in l3 switch. now we want to use routing protocal to connect all the plant.
the problem is if we use the gatway of every vlan is configured in one plant. if we configured gatway of every vlan in their plant gatway switch, then multiple plant and all have same gatway. how we route them. is it possible without changing their gatway. see attachments for batter understanding.

[Seb Rupik]

Hi there,

The only way you will get around the duplication of these subnets at each plant will be to implement NAT at each plant. The problem you will encounter is that NAT is not supported on L3 switches, so you will need to use a Router to perform that function.

For most outbound plant connections dynamic NAT will be sufficient, but if an IP service is located inside a plant which is required by other plants, then you will need to configure static NAT. For this reason you should allocate a unique subnet to each plant to provide these outside addresses for the static translations. This subnet along with the outside WAN interface would be what is advertised by your IGP between the plant sites.

Cheers, Seb.