Ignore dummy0 - you enabled this particular _dummy_ and _useless_ interface
when configuring the kernel, but it won't harm you at all.
> and eth0 has not one.
Guess that happens because you're using the slirp transport ("Link
encap:Serial Line IP" hints so). With eth0=tuntap,,,$IP_Address_of_the_host
it would have a MAC.
> The mac address of dummy0 changes all the times that I boot uml.
Then it's choosen randomly. Getting any problem from that?
Now I built a root_fs while I was building a LFS.
When I finished it, I try to communicate to the host using slirp.
The files about network in the LFS are a little bit different to the others root_fs.
How I could not communicate to the host in the first time, I used the command
ifconfig -a (for the first time)
So I saw dummy0 for the first time.
I thought that it was the problem.
After your explanation, I understood that I can not worried about dummy0. I
changed some files in the LFS and I can communicate to the host using slirp and tuntap too.
Probably my question was very short but you understood my doubt.
How I am newbie, sometimes I make some silly questions.