NAT Proxmox fails

redxlus

Member
Apr 4, 2018
13
1
21
25
I continue with the topic of networks. I have a practical case, this time is to create a network (for a hypothetical company) and divide it into several subnets. The most normal thing would be to divide it with the mask but if one computer changes the mask the others will be seen.

So it occurred to me to use several Nat = range of Private IPs that share the same Public IP. With a DHCP Server in LXC with Debian to give the IPs of each network.

following the official Wiki: https://pve.proxmox.com/wiki/Networ...ith_tt_span_class_monospaced_iptables_span_tt

Code:
auto vmbr0
iface vmbr0 inet static
        address  192.168.1.20
        netmask  255.255.255.0
        gateway  192.168.1.1
        bridge-ports enp4s0f0
        bridge-stp off
        bridge-fd 0

auto vmbr4
iface vmbr4 inet static
        address  10.10.10.1
        netmask  255.255.255.0
        bridge-ports none
        bridge-stp off
        bridge-fd 0

        post-up echo 1 > /proc/sys/net/ipv4/ip_forward
        post-up   iptables -t nat -A POSTROUTING -s '10.10.10.0/24' -o vmbr0 -j MASQUERADE
        post-down iptables -t nat -D POSTROUTING -s '10.10.10.0/24' -o vmbr0 -j MASQUERADE

Work works. Give the IPs and have Internet access. But I create an another NAT (vmbr3 - 10.20.10.0/24) and this happen:

  • From the machines in NAT (both networks: 10.10.10.0 and 10.20.10.0) you can see the other machine in LAN with 192.168.1.67.
  • From 192.168.1.67 you can not see any of the NAT networks. Neither 10.10.10.0 nor 10.20.10.0
  • From the NAT machines they see each other even though they are in different networks: From 10.10.10.0 to 10.20.10.0 and successively.
My doubt is that because they see these two networks if they should be separated. And how to properly do the division.

Thanks all !
 

About

The Proxmox community has been around for many years and offers help and support for Proxmox VE, Proxmox Backup Server, and Proxmox Mail Gateway.
We think our community is one of the best thanks to people like you!

Get your subscription!

The Proxmox team works very hard to make sure you are running the best software and getting stable updates and security enhancements, as well as quick enterprise support. Tens of thousands of happy customers have a Proxmox subscription. Get yours easily in our online shop.

Buy now!