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Routing between 2 subnets

Posted: Tue Feb 04, 2020 12:50 pm
by ramirez
Hi everyone...I am going through a brain freeze so I'd like to ask for your advice...

I am running a DHCP client on eth1 and the port has received 192.168.0.27

I am running a DHCP server 192.168.10.0/24 on Wlan (its static address is 192.168.10.10)

I would like for devices connected on Wlan to be able to access the internet (eth1 has internet) and ping other devices on the 192.168.0.0/24 network, without bridging them together (Wlan and eth1)

It's probably a routing rule in ip/routes I need to include but like I said...brain freeze!

Thank you

Re: Routing between 2 subnets

Posted: Tue Feb 04, 2020 2:45 pm
by mkx
Unless devices in 192.168.0.0/xx (I assume xx is 24, could be some other value) network are aware of your RB (at least the upstream gateway would have to be aware of it) acting as gateway between the two subnets, you have to perform NAT on your RB exactly the same way as you would do it if ether1 was WAN (internet) interface.

The only problem with the above proposed solution is that devices from 192.168.0.0/xx subnet will not be able to ping devices on 192.168.10.0/24 subnet nor will they be able to initate connection towards devices in 192.168.10.0/24 subnet. All connections initiated by devices from 192.168.10.0/24 subnet will appear as if they originated from RB (192.168.0.27/32) ...

Re: Routing between 2 subnets

Posted: Tue Feb 04, 2020 5:00 pm
by ramirez
I see, thank you MKX, unfortunately I need both ways communication... between 192.168.10.0/24 and 192.168.0.0/24 :-(

Re: Routing between 2 subnets

Posted: Tue Feb 04, 2020 6:08 pm
by mkx
In that case, you'll have to add static route on default gateway of 192.168.0.0/xx network ... destination 192.168.10.0/24 gateway 192.168.0.27.

If you can't do that (e.g. you're not router administrator and that person won't do it), then it can't be done.

The only remaining option then would be to use your RB as switch, i.e. your devices will be in 192.168.0.0/xx subnet.

If limited communication is acceptable, you could follow the NAT path and configure some port forwarding ...

Re: Routing between 2 subnets

Posted: Tue Feb 04, 2020 7:55 pm
by Sob
You could also add this route to individual devices in 192.168.0.0/24 network (if you'd have access to them but not to gateway), but it's not very practical solution (possibly too many places where it would have to be done).

Re: Routing between 2 subnets

Posted: Wed Feb 05, 2020 4:59 pm
by ramirez
Yeap that did the trick...Thanks a million!!!