Hi everyone, good afternoon.
I would like to ask you a favor to help me on below issue.

Let me explain the environment:

1) I have one generic modem (192.168.25.1)
2) I have one router ArcherC8 (192.168.0.1)

3) The router ArcherC8 has the internet interface connected to one interface from modem and the internet/wireless is working properly

4) I have one CentOS 7 with two ethernet cards (1 connected to the router, the ip address is 192.168.25.200) and (1 connected to the modem, the ip address is 192.168.0.200)

5) I have opened the FTP port (20 and 21) on modem
6) I have used the port forwarding for both ports (20 and 21) pointing to my CentOS ethernet card 192.168.25.200

7) I can establish connection on FTP server (locally and remotelly) but when I type the command `dir` or `ls` or simple upload some file, I am getting the error message "ftp: connect: No route to host"

8) The port 21 is opened on CentOS as per below command:

[root@alpha01 ~]# firewall-cmd --list-all
public (default, active)
interfaces: enp1s0 enp4s0
sources:
services: dhcpv6-client ssh
ports: 21/tcp
masquerade: no
forward-ports:
icmp-blocks:
rich rules:

So, am I missing anything else on this configuration?

If possible, please provide a quick guidance, I tried to search help on internet but nothing works.

I appreciate any help and attention.

Rafael Vilela

I'm not much of a CentOS guy, but did you try this?

according to many links I read on the net it's required:
https://www.unixmen.com/install-conf...rver-centos-7/
http://codingbee.net/tutorials/rhcsa...an-ftp-server/

Thank you jnihil.
I have solved the issue by upgrading the firmware of my modem to use it as bridge instead of router, and have my router doing the pppoe services. My router has many options in terms of port forwarding, NAT, firewall, so this decision was good.
I am now able to connect remotelly and use ftp services.

Thanks again