Hi! I want to connect 3 Mikrotik router.
I can connect 2 router together, but the third router cant connect to the first router..
WAN ↔ R1 ↔ R2 ↔ R3 ↔ PC
what must I do?
It all depends on your configuration of all three devices.
Why do you need or want to connect 3 routers back to back?
What are you expecting from such connection?
I need this on occasion. You must route the network IP/subnets back to each router on the downstream router. What are the IP/subnets assigned to each of these router interfaces? That would be the P1 and P2 on each router.
WAN ↔ P1-R1-P2 ↔ P1-R2-P2 ↔ P1-R3-P2 ↔ PC