LAN clients not getting DHCP ips

Installing and Using OpenWrt
21

What the the OpenWrt's wan IP?

22

192.168.7.200

23

And the OpenWrt VM cannot actually ping the gateway at 192.168.7.1?

Do other devices on that network (specifically those that are native hosts, not VMs) have success in reaching that gateway via ping?

24

Everybody can ping OpenWrt container.
Nobody except OpenWrt container can ping the gateway (192.168.7.1) and beyond (internet).

25

I'm confused...

Earlier, you said:

and also this:

Maybe it would be helpful to be more specific:

  • Can the OpenWrt VM itself reach the main upstream gateway 192.168.7.1?
  • Can OpenWrt reach the internet? If not, please further clarify with ping tests to:

Next,

  • Can other devices (real standalone hosts, not virtualized) on the 192.168.7.0/24 network reach the router at 192.168.7.1?
  • Can they reach the internet?

Finally,

  • Can devices (standalone non-VM hosts) on the 192.168.18.0/24 network reach the OpenWrt router (192.168.18.1)
  • Can those devices reach 192.168.7.1?
  • And can those devices reach the internet normally
26

Apologies, if I was confusing.

Can the OpenWrt VM itself reach the main upstream gateway 192.168.7.1?

Yes, as well as the internet and every host in 192.168.7.0/24 and 192.168.18.0/24.
Everything works fine on it.

Can other devices (real standalone hosts, not virtualized) on the 192.168.7.0/24 network reach the router at 192.168.7.1? Can they reach the internet?

Everything works perfectly fine on the 192.168.7.0/24, on all devices with IP in that range.

Can devices (standalone non-VM hosts) on the 192.168.18.0/24 network reach the OpenWrt router (192.168.18.1)

Yes

Can those devices reach 192.168.7.1?

No

And can those devices reach the internet normally

No.
The furthest they can reach is the external IP of OpenWrt container, which is 192.168.7.200

27

Can you verify the upstream router's lan subnet (192.168.7.1)? If seems to me that there could be a conflict here (i.e. if this is a /19 or subnet mask 255.255.240.0, that would cause a routing conflict).

28

Upstream router's lan subnet (192.168.7.1): 255.255.255.0

29

This sounds like an issue with the container/VM environment. There is nothing that I can spot that is wrong with the OpenWrt side of things, I'd look at the firewall (if any) on the main/host OS of the system that is running the OpenWrt container, and I'd also look at the configuration of the virtual environment.

Instead of using a bridge br0, maybe you'd have success if you directly connect OpenWrt to eth1.

30

Well, I circumvented both issues by LXD-exporting the working OpenWrt instance (192.168.7.1) and importing it on the desired host.
Things seem to work fine, now. I don't know if it was some bug, but I wasted so many days trying to fix it, I am no reluctant to spend any more time on it.

Thank you all kindly for your time and input!