Howto route some content like .mp3 to 2nd WAN link

RouterOS Beginner Basics
1

I have 2 wan links connected with mikrotik.
I want to route some contents e.g .mp3 .flv to 2nd wan link

I know how to route traffic based on ports/ips, but howto route using content ?

2

Hi,
I don’t ever try this but I think you have to create a L7 Firewall rule that can determine file extension you need. Then go to / IP firewall mangle and mark routing which packets have such L7 firewall rule condition.

http://wiki.mikrotik.com/wiki/Manual:IP/Firewall/L7
http://wiki.mikrotik.com/wiki/Manual:IP/Firewall/Mangle

3

This is impossible to do if you’re doing NAT on your WAN links.

Long story short: NAT happens on the first packet of a connection. For downloads that’s the initial TCP SYN. You can’t know whether an HTTP connection is downloading an MP3 file until the 4th packet at the earliest. At that point it’s too late to pick WAN links - you can’t swing it to the other one anymore because NAT on the first packet has tied you to whatever WAN link you picked for the first packet.