FTP problem

[ksparam]

Hi ,

We are having a SUN server which is located in DMZ, means will have a pulic IP. Want to FTP to other server which is in internal network. We have done the configuraion, but giving problem.

We are able to connect to the server which is in intranet(internal network), but not able to execute any FTP commands. For example if you say "ls" it just hangs for coule of hours also. It doesn't respond at all. Then we have to press ^C to come out of the session

The internal server is having Windows NT operating system.

Don't know the problem is from NT or SUN, can some one help me in solving the same.

Thanks

 

[KenCunningham]

Have you tried dir rather than ls?

 

[ksparam]

Yes, I have tried dir also. it just hangs if you type any command

 

[marrow]

Have you ftp'd from the NT box to the Sun?

 

[coffeysm]

Do they allow both ports 20 and 21 back into the internal network? I had an instance where the network guys blocked port 20 at a remote site and recieved the same problems you did.

 

[Willemvrm]

I am not quit shure how ftp is working but it uses two connections. A data connection for...data and an controll connection for the commands.
Could be this is, as coffeysm is writing, the difference between port 20 and 21.
When 20 is the controll port and 21 the data port and somewhere port 20 is blocked you would have a data connection but are not able to sent any commands.

You could run a snoop to check what data is being sent and received.

There is probably someone out there who can verify this to be true or rubbish.

 

[ksparam]

Thank you very much.

Will check on port 20 and 21. In the mean while can you please tell how to run snoop.

 

[coffeysm]

As root open two terminal windows and type in snoop port 20 and snoop port 21. Then have someone try FTPing you should be able to see all the traffic. If you can also run the same commands remotely on the other server, to see what it has.

 

[dsm666]

Check this out, hopefully it sheds some light on the matter:

http://www.dslreports.com/forum/remark,1381832;root=equip,16;mode=flat..

Definitely a data port issue..