1. try if you can ping the router's IP (else check cable connection)
2. try if you can ping your DNS server's IP (else check default gateway setting)
3. try if you can resolve addresses by pinging by name instead of IP (else check DNS settings)
4. if all above works and the FTP connect fails, it's your router and/or FTP setup
Note that pings might fail because the devices/hosts are set up to not answer them.
