What are the downsides of having the Omnia behind a NAT?


I’ve read here that it’s a pain to have the Omnia behind a NAT, but other than having to do double work when port forwarding, what are the downsides of having the Omnia behind a NAT?
I’m primarily asking because it might be a bit harder than I thought of setting my ISP router to bridge mode.

Thanks in advance!

I’ve spoken in the IRC channel and I want to thank @Pepe for the conclusion of the following summary:

  1. Double work of NAT (NAT of ISP router and NAT of Omnia)
  2. Little more latency because of the IP packet processing of the ISP router.
  3. Possible ingress / egress bandwidth limitation of the ISP router.

Feel free to discuss / add to this list :slight_smile:

Port forwarding will have to be configured at both routers.
Upnp will not work as expected (which might not be a bad thing, security-wise).

with 1:1 NAT there should be no need to setting port forwarding on both devices AFAIK.
Latency will be bit higher as you mentioned and UPnP is questionable.

What is 1:1 NAT? If we are talking abot simply only connecting the secondary router to the first, so that the primary router will only ever talk to one connected LAN machine, the secondary router, I believe there is no guarantee that the typical port remapping NAT will keep port numbers unchanged (I would assume that linux NAT attempts to keep port numbers unchanged, but there is as far as I can tell no hard guarantee). If you talk about configuring the primary router to forwarding everything to the secondary, that I agree that configuration will only needed once, unlike specific port forwards.

Yes, I mean that first router will forward all ports to one IP behind him (TO)