My setup is simple : i have two EoIP tunnels going to the same destination IP from a RB750G.
I want the first tunnel flowing through ISP1, and the second tunnel flowing through ISP2.
ISP1 and ISP2 are two wan interfaces on the Mikrotik.
How can i do this ?
Actually the only way i’ve found to do it is to use a second IP destination address. But i need to send the tunnels to the same one.
Thanks for your help.
Yes, it is the correct way [to use another destination address]. As there is no way to filter EoIP tunnel by tunnel id in /ip firewall.
… and no way to set local-address, like in IPIP tunnel 
It would be nice if we could filter by EoIP tunnel ID inside mangle rules. Is it technically possible ?
See my reply above.
It is not possible to have another IP address on public ADSL links. Sometimes we need to terminate the tunnels from public ADSL to puclic ADSL.
IPv4 address are more and more expensive here.
Please implement IPv4 over IPv6 EoIP tunnels, so that we can use IPv6. We have IPv6 here on public ADSL links for the same price.
IPv6 will solve the destination address problem, because we have a /48 for each link.
Is it technically possible ?
Well something tells me you could try to sniff some EoIP packets, see what the part with the tunnel-id looks like, and then create a L7 rule to match GRE packets with that substring. However you better be proficient with regular expressions 
And, as always, L7 rules definitely stress the CPU a lot, so you might run out of resources with very fast links, as EoIP itself is already quite a strain on the CPU when carrying a lot of traffic.
Yes, i did thought it was possible to do this, but doing the regex L7 filter would be quite complicated, and in the end can stress the CPU.
It would be a lot simpler if we could filter by tunnel ID.
Matching by tunnel ID would permit as well to give a different priority for each tunnel when there is no other means to match.