VLAN routing (communication between 2 IP adress with diferent subnet)

[LuisDoMtz]

Hello everyone, I have a question... is it possible that two IPS in different network segments can see each other through communication between VLANs?

For example I have two different IPs one is

10.147.158.xx and with subnet mask 255.255.255.0 and the other IP is on 10.0.0.xx with a subnet mask 255.255.0.0.

I have already created two VLANs on a scalance XC208 manageable switch and I still don't know how to communicate those two VLANs so far I have simply put the network cables one from a SIEMENS 1500 PLC and the other from the PC and I can't see each other by Pinging it. The two network cables I have put one in each port (2 ports in total dedicated to the 1st VLAN) and doing Ping between them I can't see them so this gives me to think that even if I manage to communicate between different VLANs I still can't make the two devices see each other.

As a note: it is not possible to change IP addresses due to company policies.
Company

I don't know if I should get a gateway to modify the IP on one side and on the other side put the IP I need or if the scalance XC208 manageable switch can do it.

Sorry if I can not put them in context but they are my first beginnings with networking and VLANs issues.

I hope some of you can help me

Thanks in advance

 

[TheWaterboy]

vLans will often have a firewall between them where you can assign access rules for the machines that need to traverse between them. In that scenario the firewall becomes the gateway setting and therefore the gate keeper.
Crossing the vLan should be the exception and not the rule. If you are trying to do so without IT knowledge and assistance, it could cost you your job.

 

[PreLC]

Just from a technology standpoint, it's possible: You need to understand your plant's networking infrastructure.

Is there a layer 3 NAT available through your IT team?
In case it's a yes or no: you can accomplish this quite easily with a layer 2 NAT, Network Address Translation is exactly meant for this application. The scalance switch is advertised as a layer 2 switch. It should be capable to do this exact thing.

 

[harryting]

To make them talk to each other you need a router or a NAT device.

You raised some red flags:

- you said you are not allowed to change IP. So was the segregation intentional? If so, you shouldn't mix the two network together?

- you might be mixing terminology. Just guessing. VLAN is not the same as subnet. You can have VLAN with the same subnet (confusing but allowed). One don't even need to create VLAN on a switch to run multiple subnet (they won't talk to each other without a router).

I recommend you discuss what you doing with higher up and also get a better understanding of basic subnet (tons of video online).