Hello friends, I am ISP I have 4 working lines, I only want youtube traffic to go to my 5 lines, how is that?
1 2 3 eo link
5 lines vdsl
The problem is not as simple as it sounds. You would need to know all the domains/ips that youtube gets content from. Then you would have to add those to a list and mark this traffic to the right wan. In theory you would do that with Layer7 if youtube always used youtube* domains but I do not think they do.
layer7 can not see inside https, like any other things
The only way is by routing, but also redirect all the other non-youtube-traffic on same IPs
obviously until is not used only tls 1.3, some of unencrypted sni on tls 1.2 and lower can reveal the remote domain on old browser or app
Why?
Its not practical and not likely possible.
There are very expensive other devices which can do this sort of work. Get the right tool for the job.
You can try to use a shovel to dig a narrow cylindrical hole but you will fail.