cannot open connection network is unreachable - raspberry-pi

Question

I want live streaming on YouTube from my Raspberry Pi 3. The script properly work when I run the manually from shell. When I add that script in the file sudo nano /etc/rc.local to run it automatically on startup it run only first time when the Raspberry Pi starts next time its stop working and give an error 'cannot open connection network is unreachable'.
here is the script that i use for live streaming on YouTube from Raspberry Pi.
raspivid -o - -t 0 -vf -hf -fps 30 -b 6000000 | avconv -re -ar 44100 -ac 2 -acodec pcm_s16le -f s16le -ac 2 -i /dev/zero -f h264 -i - -vcodec copy -acodec aac -ab 128k -g 50 -strict experimental -f flv rtmp://a.rtmp.youtube.com/live2/[your-secret-key-here]
I want to run this script automatically each time when the Raspberry Pi startup without any error.
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Answer 1

After caring out many attempts I found the solution.
It is very Simple. just make a new python file with any name in my case livestream.py and paste the code.
import os
os.system(raspivid -o - -t 0 -vf -hf -fps 25 -b 600000 | avconv -re -ar 44100 -ac 2 -acodec pcm_s16le -f s16le -ac 2 -i /dev/zero -f h264 -i - -vcodec copy -acodec aac -ab 128k -g 50 -strict experimental -f flv rtmp://a.rtmp.youtube.com/live2/[your-secret-key-here]
)
It can be be run by installing php in Raspberry Pi by using this script
sudo apt-get install php5-fpm php5-mysql
and run file livestream.php the php code is
<?php
exec("raspivid -o - -t 0 -vf -hf -fps 25 -b 600000 | avconv -re -ar 44100 -ac 2 -acodec pcm_s16le -f s16le -ac 2 -i /dev/zero -f h264 -i - -vcodec copy -acodec aac -ab 128k -g 50 -strict experimental -f flv rtmp://a.rtmp.youtube.com/live2/[your-secret-key-here]
");
?>