connect 192.x.x.x and 10.x.x.x

[AmityAdmin]

I currenty have our network 10.x.x.x with several VLANS, we had a Fuel Cell installed by the power company and they use 192.x.x.x we need the two networks to talk as the Siemens controller on their side needs to talk to the Siemens controllers on our side. I thought I could do this with a VLAN, but have not had any luck. I set the VLAN up and connected their controller to a port on my switch and had this port set to VLAN 700 and tagged the other VLANS that need to see this, then I tagged the ports for the other controllers and server with this VLAN as well. I set up some routes so any IP with the 192.x.x.x would get routed to this switch, if I do a tracert at this point it goes to the correct switch then goes to my core switch and keeps going in this loop. I then tried giving VLAN 700 and IP address in the 192.x.x.x network and tried tracert again and it went to the switch then just failed. If I put a 192.x.x.x address in the sever as a second address it works but I can not do this to the Siemens controllers. Does any one have any idea as to where I am going wrong? Can I even do it this way? Thanks Kevin

[Vince-Whirlwind]

We need to see your config.

I think you seem to have misunderstood how VLANs work - you don't assign a different VLAN to your 10. controllers so they can communicate with that other VLAN. That's not at all how it works.

The two different subnets are in two different VLANs.

To communicate, the devices send packets to their default GW.
The default GW is the router address assigned to their VLAN interface on the router/Layer3 switch.
The router/Layer3 switch then routes the packets to the other VLAN.

[AmityAdmin]

I have the two fifferent subnets in two different VLANS VLAN700 is for the 192.x.x.x and VLAN155 if for the 10.x.x.x. I believe my issue is the default GW as the contrator doing the Siemens work will not put a default GW in the settings on that controller and from what I understand from what you posted this would be required to connect them.

Thanks for your post and help.

[Vince-Whirlwind · Accepted solution]

The only other way to do it would be to put your controllers that need to talk to their controllers in a 10. network that overlaps with theirs.
This woulkd depend on what their subnet mask is.
Then you either - 
 - put your controller on the same VLAN
or
 - bridge the two VLANs

So long as the two different groups of controllers think they are in the same subnet, they will commkunicate with each other at Layer2.
Your own controllers can still have a default gateway and communicate via Layer3 with other subnets, so long as the network they are in (as defined by their subnet mask) doesn't overlap with anything else you use.