Outbound NAT working wrong in v22

[elvinmammadov]

Hello,

We have noticed that, in the version 22, there is a problem with Outbound NAT.
So, for example, there are multiple WAN interfaces.
WAN_M - 10.10.10.1
WAN_C - 10.10.10.2
WAN_E - 10.10.10.3.

In the Outbound NAT, I create a rule for:
LAN_M to NAT Address WAN_M
LAN_C to NAT Address WAN_C
LAN_E to NAT Address WAN_E.

But in this case, all interfaces shows the correct public ip until we reboot the Opnsense. After reboot all interfaces shows the public of of WAN_C - 10.10.10.2. We think it takes them in alphabetic order, because the end of interfaces name is WAN_C.

[Patrick M. Hausen]

Multiple interfaces or multiple addresses on one interface? What's the netmask associated with each interface?

[elvinmammadov]

Thank you for your reply. We get 3 DHCP WAN addresses which are in same subnet /26. We have created 3 WAN Interfaces with DHCP.

[Patrick M. Hausen]

That is not going to work. You cannot have more than one interface in the same network. You must use either completely disjunct networks or one interface and alias addresses.

[elvinmammadov]

We get IP address from Hetzner Datacenter and they bind ip address to mac address. In this case, we must have separate WAN interfaces with the MAC Address from Hetzner. But it worked till now in this way. We have other servers with this structure with Opnsense V21.

We have made it working in this way in Outbound NAT.

Interface: WAN_C
Source: LAN_M
NAT Address: WAN_M_address

Interface: WAN_C
Source: LAN_C
NAT Address: WAN_C_address

Interface: WAN_C
Source: LAN_E
NAT Address: WAN_E_address

The first public ip of Opnsense is WAN_M.

In the previous versions, we have always chosen the first WAN Interface for NAT Outbound Interface and it worked well. But starting v22, it doesn't work, instead we need to choose the interface in alphabetic order.

[elvinmammadov]

The same problem still exists in the latest version V22.7.7_1.