Strange FTP problem

[Dan Rosen]

Just this morning, when I try to FTP to the HP server (10.20), it just hangs. I can use FTP on the system, and I can use other protocols (WRQ's Reflection protocol). I can connect to the system, and even get a directory level, but if I try ls, it times out before files are shown.

Everything appears to be working - ftp shows up in ps, and I cycled inetd -c. No change.

Any assistance in hunting this very strange problem would be greatly appreciated!

[RAC_1]

Enable the inetd and ftpd logging. (inetd -l and ftpd -L)

Check if you get anything in syslog.log file and post. do you ahve firewall in between?? If yes, check that also.

Anil

[Steven E. Protter]

At this point, I might even suspect the client you choose.

Try a few different clients when it hangs, check the logs(prior post) and see if the behavior is consistent.

Don't discount the firewall idea either, I've seen that a few times.

Last, is the ftp server current, patched?

swlist -l product | grep ftp

SEP

[Dan Rosen]

Logging is enabled and I checked syslog. I can see connections being established, but no comments as to why browse and put/get don't work...

There are no firewalls between my machine and the server, and this situation was working last week. No changes have been made to the system over the weekend.

Thanks!

[Geoff Wild]

Try telnet:

telnet yourserver 21

Do you get a prompt back?

220 myserver FTP server (Version 5.60) ready.

How many current connections?

netstat -n |grep "XXX.XXX.XXX.XXX.21" |wc

Where XXX.XXX.XXX.XXX is ip address of your server....


Rgds...Geoff

[Dan Rosen]

I have tried Reflections (v.9) and the Win2K FTP client. I can get into the server (successful logon), but it dies when I try to access files. It is not a security based issue.

The Reflections WRQ protocol (proprietary) works, but it is about 25 times slower than FTP.

I can only see the single instance ftp connections running using netstat.

[Ron Kinner]

FTP is a bit odd in that it requires two separate TCP/IP connections. The control connection is made from port x on the client to port 21 on the server. Then when you ask for data (or just do a simple ls) a data connection is established backwards from the server port 20 to the client port x + 1. It sounds like it is having problems setting up the data connection. Usually this becomes a problem with a firewall in the circuit. Do you see the data connection on port 20 (netstat -an | grep 20)?

Sometimes you can get it to do what they call a passive connection where the client originates the data connection too. Usually the interactive command is: passive
tho with Windows IE you can tell it to use the passive mode in Advanced Options.

It could also be that the server is having a problem with DNS and is getting a different IP address back for the client name and doesn't know how to get to the client. See if you can ping clientname and traceroute clientname from the server or do nslookup clientname. Does that give the correct ip address for the client? Does nslookup A.B.C.D where A.B.C.D is the IP of the client give you the client name.

Ron