I have just installed a Cisco 877 router. Our clients need to be able to use Passive FTP to get files from dataloggas outside the network. The datafile I believe is being caught at the router. Can anyone help me with what I need to do to make sure passive FTP is working through the router?
Re: Passive FTP with Cisco 877 Router
12 years 6 months ago #14690
Hi blondeastheycome, welcome to Firewall.cx.
Passive FTP differs from 'active' FTP in that the data channel can use any port by negotiation as opposed to port 20 which is the normal FTP data channel. Its possible that your application is trying to use a port that the router is blocking hence the failure.
Have a read at
for a really good explanation.
To prove it conclusively try changing the port if your FTP application supports that. You could also try using the debug commands on the router to watch what's going on, or do a packet capture using something like Ethereal