Some outbound FTP fails

[kozmonot28]

I've got a situation that has me stumped. Our company has about 4 vendors that we often FTP to. Two of them work with no problems. The other two hang or timeout with a "ls" command. I've tried it from both a FTP GUI application and from the old fashion manual way. Both fail. I've tried it from outside our network and it works fine.

I've got a 1720 router with IOS 12.2.6 and I'm using PAT for outbound translations. I do not have any outbound access list.

I've spent all week reading everything I can find. It still won't work.

 

[liebknecht]

Hello.

I'm a newbee when it comes to routers and firewalls. It looks to me like you're facing problems similar to those you get when your not using passive ftp with your ftp client.

Have you tried to use passive ftp against the servers from inside your firewall?

Best regards.

 

[sobak]

Liebknecht is on the right track; try to set the client up for Passive FTP transfers that usually does the trick. david e
*end users are just like computers, some you can work with...others just need a simple reBOOTing to fix their problems.*

 

[Saeed42]

This might help

http://www.slacksite.com/other/ftp.html

 

[kozmonot28]

I narrowed it down to the same thing. Passive Transfer is what is letting us get to the sites that do work. The problem is that not all sites allow Passive Transfer. I worked most of the afternoon with one vendor who says he can't do passive transfer because his FTP site is protected by NAT.

 

[liebknecht]

Hello.

Once again, I'm a newbee on routers and firewalls but I just felt like put an ad-hoc question that is touching the problem that kozmonot28 has.

How do I configure my 1720 router to allow active FTP between servers outside my router aand clients inside? If I do so what security problems do I face with such a configuration. Is it possible to limit the security problems?

Thanks in advance.