here is a diagram of my network.
I have 2 networks. Network 1 has the computers, servers and 2 ftps. One ftp is filezilla, one is a asus router with external hd and has ftp enabled (the best 20€ i have ever spent! simple solution and highly effective and useful!). The network 2 has 1 computer that runs 2 virtual computers.
Mikrotik 1 has NAT port forwarding from port 21 to port 21 for FTP 1 and NAT port forwarding from port 333 to port 21 for FTP 2. This way FTP 1 and 2 are accessible from the internet. The problem is NAT port forwarding for FTP 1, because i can't connect to my outside FTP 3 which also runs on port 21! I switch NAT port forwarding from 21 to 334. This way i can access my FTP 3 and both FTPs are accessible from the internet. I have also entered this:
Problem solved! Do i realy need this firewall filter?/ip firewall filter
add chain=forward connection-nat-state=dstnat action=accept
Also make sure that you allow packets with connection-state=related. It's usually part if first standard rule.
I don't even know how to explain this, but every computer behind Mikrotik 2, so the network 2, which has its own external IP, can't connect to FTP 1 or FPT 2 in network 1. It can connect to FTP 3 (ftp outside). Or let me correct myself. It can connect, but after a period of time, i get error 10054. After the connection, it starts to fetch the directories and files of the root, but it never displays the results. The funny part is that sometimes it does work and i can browse the ftp ... 1 out of 10 times maybe ... I have cobianbackup here that can upload to ftp. The test sometimes goes through and sometimes it returns the error 10054. I also have a freesqlbackup program that also transfers files to the ftp. The test connection to the ftp works, but when the actual upload starts, it stops working ...
I entered into the mikrotik 2 NAT port forwarding for ports 333 and 334 and added the external ip, also added the same filter ... Nothing works because i don't know what i doing! I am guess the problem is with mikrotik 1 and i don't need to do anything on mikrotik 2 since it can connect to FPT 3 without any issues ... Or am i wrong? Do i need NAT and filters? Or just NAT? Please help me out.