LDantuma
asked on
Access to ftp server seems random / iptable errors
I have a local ftp server (Freecom FSG-3) running on Linux 2.6 based on Snapgear. I offer users access to images on the local ftp server (anonymous login) through a html page on a non-local webserver. When I browse to the webpage in Firefox 3.0.8, some 8 thumbnails (instead of 38) are randomly shown. I get a lot of error messages (see attachment) on iptables (also randomly). When I click all massages away, I am able to manually show each thumbnail. I can also access the real image by clicking on the thumbnail.
When I browse with Internet Explorer 7.0.6, I do not see any thumbnail. Choosing show picture doesn't help. Clicking on a non-existing thumbnail returns the error "Internet Explorer cannot display the webpage". "Enable FTP folder view" checked gives the same result. If I uncheck "use passive FTP" I get a login window when clicking on a non-existing thumbnail. No matter what I fill in, I don't get access to the image.
I tried to access the ftp files locally and using an unprotected wireless access point nearby: no difference...
Error-messages.jpg
NAT.jpg
When I browse with Internet Explorer 7.0.6, I do not see any thumbnail. Choosing show picture doesn't help. Clicking on a non-existing thumbnail returns the error "Internet Explorer cannot display the webpage". "Enable FTP folder view" checked gives the same result. If I uncheck "use passive FTP" I get a login window when clicking on a non-existing thumbnail. No matter what I fill in, I don't get access to the image.
I tried to access the ftp files locally and using an unprotected wireless access point nearby: no difference...
Error-messages.jpg
NAT.jpg
ASKER CERTIFIED SOLUTION
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
I'm not saying that it's forbiden. Just not very common and people might not see it properly (depending on browsers, their network firewalls etc.).
There are some solutions:
1. Copy the images on the server. This can be done with an automated script (cron job).
2. Create a (php or similar) script that forwards the image
For example you could call a script like:
http://server.com/ftptransfer.php?url=ftp.server.com/image.jpg
The script would connect to ftp server and returns the contents of the image.
Personally I would copy at least the thumbnails to the web server.
There are some solutions:
1. Copy the images on the server. This can be done with an automated script (cron job).
2. Create a (php or similar) script that forwards the image
For example you could call a script like:
http://server.com/ftptransfer.php?url=ftp.server.com/image.jpg
The script would connect to ftp server and returns the contents of the image.
Personally I would copy at least the thumbnails to the web server.
ASKER
I fully understand. I'm not very good at programming in php, so I opted to use the web server function of my FSG. It's online and working perfectly.
As far as security is concerned, I found no difference between ftp and http, except the fact that it doesn't matter how I protect the folder I give access to. With ftp I have to specifically give anonymous access, and the other folders are secure. With http it doesn't matter if the folder is username/password protected. Mmm, I guess I do not have a choice if I do not want to program in php.
As far as security is concerned, I found no difference between ftp and http, except the fact that it doesn't matter how I protect the folder I give access to. With ftp I have to specifically give anonymous access, and the other folders are secure. With http it doesn't matter if the folder is username/password protected. Mmm, I guess I do not have a choice if I do not want to program in php.
ASKER
By the way, the error messages mentioning target problem were due to the fact that the html-page directed to thumbnails written with lower case. So the thumbnails were not found.
I still do not understand why Firefox works better with ftp (showing me at least some thumbnails) and IE not at all.
I still do not understand why Firefox works better with ftp (showing me at least some thumbnails) and IE not at all.
ASKER
The question of different behavior in IE opposed to Firefox was not answered. Blaz did convince me that I had to use a webserver (al teast for thumbnails). It worked perfectly.
ASKER
What you're saying is that using a ftp server is wrong anyway, anyhow. Correct?
Is the only way putting the images on a webserver? Or is there an other way? I am hesitant using my FSG as a webserver, because I need a DNS-sevice and I think it is less secure.