How to see vlan networks inside lxcbr0 or lxdbr0?

When creating an LXC with:

root@myhost:~# cat /var/lib/lxc/vlan-263/config 
lxc.include = /usr/share/lxc/config/ubuntu.common.conf
lxc.arch = x86_64
lxc.rootfs = /var/lib/lxc/vlan-263/rootfs
lxc.utsname = vlan-263

# This is the config of the LAN Interface = vlan = 263 = up
# next line is the physical link of the container-host = eth1
# next line is the name of the interface inside container = eth0 = 02:00:00:00:02:63

How can I see that VLAN Interface (for VLAN 263) on the host? Ifconfig or ip a do not show it. Is it inside lxcbr0 or lxdbr0?

How can I show or see it?

You can’t. With the config above, LXC has the kernel create an eth1.263 device on the host, then MOVE it inside the container’s network namespace. When that’s done, the interface is only visible inside the container.

You could use nsenter with the -n option if you want to do something with the container’s network stack from the host:

nsenter -t $(lxc-info -p --name vlan-263 | tr -d ' ' | cut -d: -f2) -n ip a

Thanks a lot for the answer!
So where is the tagging happening?
And what role are lxcbr0 or lxdbr0 having in this setup?

In this setup, you’re not using lxcbr0/lxdbr0 at all, so they have no impact in your setup.
The tagging is directly handled by the Linux kernel, possibly even offloaded to the card itself.

Thank you very much for the info. Where could I read about that? (docs)