Multi van & van to van

NethServer Version: 7.6.1810
Module: your_module

Hello to all.
Guys - need help with building a network of vlan. My internet provider (for schools) uses settings for client equipment such as:
172.X.X.240 / 30 with the gateway 172.X.X.139 at the same time, the settings for the router’s local network should have
10.X.X.131 / 27 and the gateway 10.X.X.129.
for some time a router was used and there was no problem … until he died. There was an idea to register on van server interface 2 vlan one for example with address 172 … and the second from 10 … and actually make a route between vlans, so that 10.xx129 looked to me towards the server and my local subnet 192.168.0.1/24 had his gateway, and he (vlan), in turn, was redirected to vlan with the address 172…xxx. Well, the question itself - how to properly organize such a connection? Do the CIDR network and firewall do the bleeding from the network to the network and in the multivane set the value 1 and 100, respectively?
I will be glad to any help

Just trying to understand your situation.
How can a /30 subnetmask have an ip of 172.x.x.240 and a default gateway of 172.x.x.139?
a /30 subnetmask only contains 2 addresses so they are not on the same subnet!
Unless there is a route from 172.x.x.240 to 172.x.x.139 they will not be able to “see” each other.

Behind that router, how is your network configured? Is it NethServer running as gatewat for your LAN? In a way that you have “double NAT”: NAT from your ISP router and behind that NAT for your LAN through NethServer?

If this is the case, it doesn’t really matter what subnetmask you use on the first NAT as long it has a different subnet than your LAN subnet.

As I understand now it looks like:

Internet - ISP Modem/router [subnet 172.x.x.240/30] internal router - internal subnet 192.168.0.1/24
You want: ISP Modem/router [subnet 10.x.x.131 /27] internal router - internal subnet 192.168.0.1/24

IMO, unless you have services running in the NAT section right behind your ISP Modem/router, the subnet you use there is unimportant.

You’re right. There was an error - he wrote and was mistaken. We have modem settings:
on the van interface
172.23.175.241/30
gateway 172.23.175.242
nat off
10.61.127.130/27
gateway 10.61.127.129

on the network interface card nethserver (red) I get the address via dhcp (10.61.127.131) - then the server routes to 192.168.0.1/27

here was an idea to register these subnets on two vlans, 10.24 … (red1) and 172 … (red2) ,
and redirect red1 to red2. red1 leave as incoming on nethsever. Is it possible ?

Let me get this straight …

Router public side:
IP 172.23.175.241/30
GW 172.23.175.242

Router private side:
IP: 10.x.x.131/27

correct?

What is this gateway on the private side? It makes no sense as the GW for that side is the router itself.
So, what is this 10.x.x.129?

What are these other IP’s doing here?

From what I understand you have a school network and an assigned IP, and you want to run more then 1 machine behind that IP. Correct?

Yes. Right. School. The provider gives such settings. Everything is working. 10 network does not allow to route my number of machines.

The network of the provider has content filtering, therefore such network settings.

br0 n/a LAN (green) 192.168.56.101 EditExpand
enp0s3 08:00:27:7f:bc:cd Bridged (br0)
enp0s8 08:00:27:dc:7c:a9 CONFIGURE
enp0s8.1 n/a Internet (red) - red1 10.61.127.131 EditExpand
enp0s8.200 n/a Internet (red) - red2 172.23.175.241 EditExpand

Good. Let’s forget the addresses … Here with these settings - how to transfer traffic from enp0s8.1 to enp0s8.200 correctly?

Both are RED interfaces. You use 2 different internet connections?
If you do not have 2 internet connections, then I would suggest to remove 1 RED interface. If there are 2 internet connections, you just need to enable multi-WAN and NethServer will handle the distribution over both internet connections.
To me it is still unclear what you goal is… Maybe you can make a schematic drawing of your current and wanted situation?

The idea was to exclude router 2 and make it on vlans using nethserver. Is this possible?

You can probably exclude router 1, but I don’t know how to do it nicely and reliably