I'm stumped, and i'm hoping someone here might be able to point me in the
right direction.

My ftpd server fails when requesting passive mode from an internet client,
and therefore, file uploads are not working. I have an automated file upload
service, and the uploads are leaving zero length files.

Here's the situation.

I have a separate multi-homed server for the network firewall. I use NAT to
provide access to an ftp server running linux and wu-ftpd. This has always
worked well in the past.

Recently, my server running the ftpd daemon had a hard drive failure. I
purchased a new hard drive, partitioned it, and did a complete system
restore from my backups. Everything works, except for the ftp passive mode.

Symptoms:
1. Valid users can connect via ftp.
2. pwd command works.
3. ls command fails when client is an internet client.
4. Valid user attempts to upload file (from internet connection)...a zero
length file is created.
5. ls works perfectly when client is local network client.
6. upload works when client is local network client.
7. Firewall is on a separate machine and has not been changed.
8. Firewall machine logs all blocked packets. No packets are logged for
passive mode requests.
9. FTP server logs all errors. No errors reported for ftp service.
10. FTP logs report PASV command log when an ls command is issued....the
command DOES NOT return a directory listing.
11. Everything worked prior to the hard drive failure, and the system
restore.

I've checked for pid files, directory permissions, have replaced the wu-ftpd
rpm package. I am stumped on how to debug this problem. Any suggestions for
debugging this issue, to determine why passive mode is failing from an
internet connection, yet it works from a local network connection? I know,
it sounds like a firewall issue, however, the firewall is on a different
machine and has not been changed, it also worked prior to the system restore
of the ftp server, plus, it logs all blocked packets, and no packets are
logged during the ftp connection. Plus, i opened the firewall temporarily to
make sure, and ftp passive mode still failed.

Please help with any suggestions on debugging this? I'm looking at tcpdump,
but i need to learn the exact communication for an ftp client.

Thanks for any help you may provide.

-stefan

[ Post a follow-up to this message ]

Stefan Willmert wrote:

> I'm stumped, and i'm hoping someone here might be able to point me in the
> right direction.
>
> My ftpd server fails when requesting passive mode from an internet client,
> and therefore, file uploads are not working. I have an automated file
> upload service, and the uploads are leaving zero length files.
>
> Here's the situation.
>
> I have a separate multi-homed server for the network firewall. I use NAT
> to provide access to an ftp server running linux and wu-ftpd. This has
> always worked well in the past.
>
> Recently, my server running the ftpd daemon had a hard drive failure. I
> purchased a new hard drive, partitioned it, and did a complete system
> restore from my backups. Everything works, except for the ftp passive
> mode.
>
> Symptoms:
> 1. Valid users can connect via ftp.
> 2. pwd command works.
> 3. ls command fails when client is an internet client.
> 4. Valid user attempts to upload file (from internet connection)...a zero
> length file is created.
> 5. ls works perfectly when client is local network client.
> 6. upload works when client is local network client.
> 7. Firewall is on a separate machine and has not been changed.
> 8. Firewall machine logs all blocked packets. No packets are logged for
> passive mode requests.
> 9. FTP server logs all errors. No errors reported for ftp service.
> 10. FTP logs report PASV command log when an ls command is issued....the
> command DOES NOT return a directory listing.
> 11. Everything worked prior to the hard drive failure, and the system
> restore.
>
> I've checked for pid files, directory permissions, have replaced the
> wu-ftpd rpm package. I am stumped on how to debug this problem. Any
> suggestions for debugging this issue, to determine why passive mode is
> failing from an internet connection, yet it works from a local network
> connection? I know, it sounds like a firewall issue, however, the firewall
> is on a different machine and has not been changed, it also worked prior
> to the system restore of the ftp server, plus, it logs all blocked
> packets, and no packets are logged during the ftp connection. Plus, i
> opened the firewall temporarily to make sure, and ftp passive mode still
> failed.
>
> Please help with any suggestions on debugging this? I'm looking at
> tcpdump, but i need to learn the exact communication for an ftp client.
>
> Thanks for any help you may provide.
>
> -stefan

I think you need to put this in the conf file

AllowForeignAddress  on

By the way, what server is it?

[ Post a follow-up to this message ]

>> original message cut....
>
> I think you need to put this in the conf file
>
> AllowForeignAddress  on

First, i'm assuming you're talking about the ftpaccess config file? If
you're going to suggest a config file on a linux system, please try to
provide the name of the file, as I'm sure anyone without a good
understanding of linux might be confused as to which of the 100's of config
files you might be referring to. Its kinda like saying "just load the dll"
to a windows programmer.

The AllowForeignAddress appears to be a configuration directive for the
ProFTPD package. If you had read my previous message earlier, you might have
noticed i said i was running linux and wu-ftpd package...so it seems silly
to me to suggest a configuration directive for a different ftp software
package.....

Also, a little attention to reading, and you might realize that I said i did
a complete system restore, which one would then assume, the config files
which worked before, are the same config files in use now, and therefore,
the odds of an improper config file are quite slim.

> By the way, what server is it?

If you're asking the server...well....this is the linux.redhat.misc
newsgroup...so let me start by saying i'm running linux redhat. If you're
asking which ftp package I am using....try reading the original message a
little more closely...as I said...wu-ftpd. Or perhaps you'd like to know
that its a Pentium 4 Dell server????? ;-)

[ Post a follow-up to this message ]

Stefan Willmert wrote:
 
>
>     First, i'm assuming you're talking about the ftpaccess config file? If
> you're going to suggest a config file on a linux system, please try to
> provide the name of the file, as I'm sure anyone without a good
> understanding of linux might be confused as to which of the 100's of
> config files you might be referring to. Its kinda like saying "just load
> the dll" to a windows programmer.
>
> The AllowForeignAddress appears to be a configuration directive for the
> ProFTPD package. If you had read my previous message earlier, you might
> have noticed i said i was running linux and wu-ftpd package...so it seems
> silly to me to suggest a configuration directive for a different ftp
> software package.....
>
> Also, a little attention to reading, and you might realize that I said i
> did a complete system restore, which one would then assume, the config
> files which worked before, are the same config files in use now, and
> therefore, the odds of an improper config file are quite slim.
> 
>
> If you're asking the server...well....this is the linux.redhat.misc
> newsgroup...so let me start by saying i'm running linux redhat. If you're
> asking which ftp package I am using....try reading the original message a
> little more closely...as I said...wu-ftpd. Or perhaps you'd like to know
> that its a Pentium 4 Dell server????? ;-)

Let me use your tone then. When I say "what server", I mean, of course,
"what server", not "what operationg system is the server running on". I
don't remember reading wu-ftpd in the original message. If it was there,
you could have easily said "wu-ftpd" instead of writing a novel. In order
to name the file, I would have had to know what server it was, but I didn't
know that at that time. Since I didn't know what server it was I, at least,
said how I solved the same problem I had with ProFTPD. Well, that was of no
use to you. Now, I am sorry that I responded at all. Let me put this in my
notes "Do not respond to Stefan Willmert's messages anymore".

[ Post a follow-up to this message ]

"Fikret Skrgic" <skrgic@comcast.net> wrote in message
news:YgM_c.299475$eM2.140919@attbi_s51...
> Stefan Willmert wrote:
> 
[vbcol=seagreen]
> Let me use your tone then. When I say "what server", I mean, of course,
> "what server", not "what operationg system is the server running on". I
> don't remember reading wu-ftpd in the original message. If it was there,
> you could have easily said "wu-ftpd" instead of writing a novel. In order
> to name the file, I would have had to know what server it was, but I
didn't
> know that at that time. Since I didn't know what server it was I, at
least,
> said how I solved the same problem I had with ProFTPD. Well, that was of
no
> use to you. Now, I am sorry that I responded at all. Let me put this in my
> notes "Do not respond to Stefan Willmert's messages anymore".


hahaha. I knew there was going to be a response...ok...i was a little harsh
(my apologies)...but if you're going to be in a technical field..you have to

1. Learn to read docs a little more closely.
2. Learn to be a little more explicit when you reply...otherwise the reply
is worthless. If you had replied like that to a bug in our bug system, I
would have kicked it right back to you to provide a much more thorough
explanation.
3. Use a little common sense when thinking up solutions....it should be
appropriate to the problem.

and just for your information: here's webster's definition of a "server"

a computer in a network that is used to provide services (as access to files
or shared peripherals or the routing of e-mail) to other computers in the
network

In YOUR eyes...a server may mean "software". But to many, it may mean a
computer...and to others yet...it may mean "someone who serves food"...;-)

[ Post a follow-up to this message ]

Stefan Willmert wrote:


> In YOUR eyes...a server may mean "software". But to many, it may mean a
> computer...and to others yet...it may mean "someone who serves food"...;-)

And you should be smart enough to figure out which meaning applies from the
context. Also, I told you I missed where you said that it was wu-ftpd. So
all this blah-blah is bullshit.

[ Post a follow-up to this message ]

"Stefan Willmert" <stefanw@this.is.fake.intellanet.com> writes:
> "Fikret Skrgic" <skrgic@comcast.net> wrote in message
> news:YgM_c.299475$eM2.140919@attbi_s51... 
> 
> didn't 
> least, 
> no 
>
>
> hahaha. I knew there was going to be a response...ok...i was a little hars
h
> (my apologies)...but if you're going to be in a technical field..you have 
to
>
> 1. Learn to read docs a little more closely.
> 2. Learn to be a little more explicit when you reply...otherwise the reply
> is worthless. If you had replied like that to a bug in our bug system, I
> would have kicked it right back to you to provide a much more thorough
> explanation.
> 3. Use a little common sense when thinking up solutions....it should be
> appropriate to the problem.

Criticizing those who try to help compounded with sarcasm is hardly a
way to encourage people to volunteer "free" help on this
newsgroup. When you are paying for support, you may be entitled to
expect a higher level of service and rigor. However, the nature of
Usenet help is that if you bite the hand that tries to feed you then
neither that hand nor the hand of others is likely to attempt to help
you in the future.

You are lucky that Fikret appears to be such a gentleman. Others would
have been much less kind in response.

Good luck getting help in the future on this newsgroup,
Jeff

[ Post a follow-up to this message ]