Hi, I recently switched from openwrt to lede, but ethernet is different here. Most notably I have extra interface eth0.1, which is actually non existant in tp links I mostly use (tl wr841n v8-v11). If I look into logread, I see eth0 and eth1, which are those real ports openwrt uses. Lede comes with "fake" eth0.1, sorry for that word. I wanted to bridge wan and lan ports on one of routers to use it as wifi client and 5 port switch and what I actually do is bridge (non existant) eth0.1 and eth1. Now I have 3 interfaces, eth0, eth0.1, eth1 on lede. On openwrt I had 2 real interfaces eth0, eth1. Everything works, but this does not make any sense to me and I find it confusing. Can anyone please explain? Thank you.
I think that it is a recent config change, that the default network config is "tagged" and uses ethX.1 for lan (instead of ethX) to make it easier to add VLANs (as you do not have to change the basic LAN ethX to ethX.1 first).
https://git.lede-project.org/?p=source.git;a=commit;h=73d923ed6baabe3f8844f13216c50a6383a79a46
I see, thank you. So I guess I will have to live with that one extra interface, which is actually not there, right?
...drastly reducing the likelyhood of soft-bricks.
Funny is, that I tried to bridge eth0 eth1 first as I have been used to, which actually led to a soft brick 
So the fake interface seems to be eth0 now.
You question was actually interesting as the change can go unnoticed for a long time if you sysupgrade and preserve settings.
I had cleared my settings last time a few weeks ago, and have since then sysupgraded test builds some 10 times, but I still had the old default network config. I tested now "firstboot" to reset the router and to get the current defaults. And now I got eth1.1 and eth0.2 
Hi, I recently switched from openwrt to lede, but ethernet is different here.
Most notably I have extra interface eth0.1, which is actually non existant in
tp links I mostly use (tl wr841n v8-v11). If I look into logread, I see eth0
and eth1, which are those real ports openwrt uses. Lede comes with "fake"
eth0.1, sorry for that word. I wanted to bridge wan and lan ports on one of
routers to use it as wifi client and 5 port switch and what I actually do is
bridge (non existant) eth0.1 and eth1. Now I have 3 interfaces, eth0, eth0.1,
eth1 on lede. On openwrt I had 2 real interfaces eth0, eth1. Everything works,
but this does not make any sense to me and I find it confusing. Can anyone
please explain? Thank you.
eth0 and eth1 are the physical interfaces
eth0.1 is vlan1 on eth0. This talks to the switch on vlan1, which it is then
configured to put on all the LAN ports on the back of the router.
This is far more flexible than not using a vlan on this connection, and pretty
close to zero overhead.
Many/most current routers require that vlans are used as both the LAN and WAN
ports on the back of the box are connected to the same switch.
As far as configuration/routing goes, eth0.1 is what you will use for all your
LAN connections, it's eth0 that you will almost always ignore.
David Lang
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