Untangle LAN help

Hi all,

First time on this forum. Big fan of the YouTube channel so figured here would be a good place to ask for some thoughts.

Basically, I think I am being an idiot. I’m missing something obvious but for the life of me, I cannot find it.

Running Untangle V16.2 on a Z4 appliance.

eth3 is for the WAN going directly to the internet.
eth0 LAN Gateway
eth1 Test LAN Gateway

Both LAN’s can go to the internet, all good. However, I can’t seem to get traffic to route across to each other. I need them separate for a specific requirement. Using VLAN’s will not be suitable for this project I am working on.

I have followed the Untangle website which just says to uncheck NAT on each LAN interface and all should be good… It ain’t. I have tried adding routes but I get conflict alarms.

I have seen other forums suggesting Filters etc. but this seems overly complicated and unnecessary for what I see as a simple issue. It’s routing 101 but I think I have looked at this problem for so long, I can’t see the wood for the trees.

Any advice would be much appreciated.

Thanks for joining.

If you wish internal networks to be able to speak with each other (ie should be able to reach on a different interface) then you do not want to NAT between those networks.


Hi Tom,

Indeed. So I have turned the NAT off on both LAN interfaces but, I still get nothing. I can ping the interface address but, nothing further behind it.

Interestingly, last night out of desperation, I enabled NAT on the interface and I got communication across to the network but, from that side from a PC I cannot ping back to the 172.xxxx side.

It’s working to the point where I can continue but, it doesn’t seem like I have got round the problem in the right way.