Using two ethernet ports

[Mellum]

Dear all,

I'm struggling with this problem for 2 weeks already. Atm I have a RevPi connect with two lan ports. The LAN 0 goes to the switch who gave internetaccess. The LAN 1 (No internetaccess) is connected to a switch with serveral profinet converters.

What I'm trying to do is from LAN 0 I want to communicate the profinet converters who are connected on LAN 1. All of the lans and converters are having the same IP address in the same range. But I'm not able to do that. I've tried a bridge but that isn't the solution what I'm looking for. Because I want to have two seperate networks. LAN 0 would be our network and LAN 1 would be the client side.

Down here a network infrastructure how it looks like:

https://ibb.co/SxP2hBV

Hope someone can help me out... I'm not sure if it is possible..

[dirk]

Hi Mellum, so in case you have two network interfaces using the same network is not a usual configuration.
There is just the Metrik which decides which interface has a higher priority.
Have a look at the Tutorial 06 – WLAN setup to get an idea what the metrik means.
Maybe someone out in the community may help you with this.

[Mellum]

Hey Dirk,

First of all thanks for your time! I know it's not a usual configuration to put them two in the same network.

The original plan is that the LAN1 would be the client side and LAN0 our company network. So do you think it would be possible if we have for example two routers?

Regards,

Mellum

[nicolaiB]

If you want to separate the two networks and implement access control, you have either to use two routers, which hide each network behinde a NAT firewall or use a transparent bridge with an firewall on top of it. For the latter you might want to look at ebtables.

Nicolai

[Mellum]

Hey Nicolai,

First of all thanks for your information.

Using a transparent bridge will merge eth0 and eth1 together right? the eth0 and eth1 should have a seperate IP address. Is this possible?

Regards,

Mellum

[nicolaiB]

Yes, but you could assign the two ips to your bridge and filter the access to the specific physical port with ebtables.

[Heimbach]

Could you have more than two IP's like that?

[Mellum]

Hi, the ip addresses are static... the eth0 has internet access and the et1 has just a ip address in the /24 subnet without any gateways or dns.