when youtube , s0.2mdn.net appear

i use nano pi M3.

when i open youtube by iceweasel ,
  ' transfering data from  s0.2mdn.net ' apear 
  and i cannot go to youtube .

what is this ?

and
how to cope with this ?

---
regards

even when i install s5p6818-debian-sd4g-20160629.img ,  i cannot go to
youtube .

The s0.2mdn.net (or any similar address) is just (one of) YouTube's ad
server(s). When you block the address in the HOSTS file, it cannot load;
but the error message is misleading; it's NOT the featured video that's not
loading, but, only the annoying ad. So, if you just sit patiently for about
10 seconds, the video will load. So, it's like blocking the annoying ad,
but you still have to wait for the duration of the ad for the featured
video to load.

Oh, and, if/when you do a GOOGLE search, you'll see various sites claiming
the s0.2mdn.net thing is a virus, and offering to let you download a
scanner that will fix it. Don't go there; s0.2mdn.net is NOT a virus, but
the pages claiming it is are trying to get you to download malware onto
your system.