Outbound and inbound FTP stopped working

kcpoole

Does anyone have an ftp server I can test uploading to?
The one my client is trying to send to does not work for me, I have my own that i use at my home and that works fine :-(

TIA
Ken

johnpoz

Valid point with the passwords - which is why there are anon tools for sniffs ;)

You could use http://www.tracewrangler.com/ to remove the passwords..

So see my first sniff where there billy password sent to ftp.microsoft – You add an anon task, set everything to passthrough except the text part. You put in the original and what you want to replace it with. See 1st attachment

You run the task, and then the new pcap it creates doesn't have your password in there ;) But all the other info is in tact for looking at what could be wrong..

You can anon other stuff as well like IPs, etc. Don't go all crazy on it, it can make it difficult to spot issues if too much manipulation is done.

replacedcopy.png_thumb

anonpasswordsout.png_thumb

kcpoole

Thanks John for the link to the anonymizer

I have rerun the capture and attached it below
Any help to work out why it is failing will be great.

note: I have appended .txt to the end of the file so i can upload.

Thanks
Ken

[Capture - FailFTP_anon.pcapng.txt](/public/imported_attachments/1/Capture - FailFTP_anon.pcapng.txt)

johnpoz

well clearly this is wrong.

So see the port command to IP 114 port 52030

Why is it trying to go to IP 170?

And where is this address coming from - see second image.

wrongip.png_thumb

wrongaddress.png_thumb

kcpoole

Ok i did not see them at all.
the Address 114 is my own server and the server on 182.50.153.244 is the host I am trying to get to
I have no idea what the other IP addresses are and what they are doing in the converstaion. thanks I will have to investigate where they fit inot it.

Ken

johnpoz

well that is not the capture you gave then..

This is 170 talking to a 88, that seems to report its IP address is 182 in the banner.

The port command yes tells this server 88 hey come talk to 114 on port 52030 for the data connection, but the SYN from 20 source port to 52030 is going to to 170. Which yeah never answers.. You see the retrans, and you see it tell it hey come talk to more ports as well where the port commands are 114, but traffic is to 170.x.x.x

You have dual wan connection on this pfsense?

kcpoole

Nope only single wan network connected

is there any possibility that somehow the port 20 traffic redirected or hacked?

What does the handling of the traffic on port 20 ?

Ken

kcpoole

@johnpoz:

well that is not the capture you gave then..

When i compare the non anoymised capture it show the correct IP addresses wher the one I posted has different IPs in it !

Sorry but the process must have changed them all. I will repost the other.

Ken

kcpoole

Okay sorry but In the original file i uploaded i anonymized the IP addresses too by mistake
Redid the process and here is the correct file

Ken

[Capture - FailFTP_anon.pcapng.txt](/public/imported_attachments/1/Capture - FailFTP_anon.pcapng.txt)

kcpoole

I note that it is the traffic returning on Port 20 that fails.
As I am using outbound NAT, how does the firewall know that the returning traffic is part of the original outbound conversation on port 21?

I assume the ftp proxy on pfsense does that magic, how do i test whether that is working properly?

Ken

johnpoz

ok 114 is the client, and 182 is the server..

your 114 box tells 182 hey come talk to me on Port X with the port command.. You see the connections from 182 to the port, but never see an answer back. Yes if this on sniffed on wan of pfsense, and 114 is behind pfsense we can see the traffic get to wan of pfsense.

Can you see the traffic at the lan interface get sent to 114?

Do you see the states get opened? What if you try a passive connection vs active. Where the client will make the connection to the server, ie so 114 will make a connection to 182 on the port 182 says to connect too.

As to the IPs being changed - remember in my post where I said to set everything else in the task to passthru ;) "You add an anon task, set everything to passthrough except the text part. " ;)

Why would you be doing an outbound nat, other than automatic? Do you have some strange outbound net setup? I would assume all traffic from lan of pfsense going to wan network would get natted to the pfsense wan IP. Ie the 114 address.

Normally in an active connection the ftp helper would change the lan IP of the server to the public, and no that hey that server is going to be coming in from source IP 20 to port X in the port command, so will send that on to the lan IP of the ftp client.

You can run into problems if that port is already in use, sure. Try a passive connection, set on 114 when you talk to the 182 server. What does the sniff show then?

Just to clarify - your the client in this conversation right, your 114 is behind pfsense. and 182 is some public ftp server? Or is 182 behind pfsense?

kcpoole

@johnpoz:

ok 114 is the client, and 182 is the server..

your 114 box tells 182 hey come talk to me on Port X with the port command.. You see the connections from 182 to the port, but never see an answer back. Yes if this on sniffed on wan of pfsense, and 114 is behind pfsense we can see the traffic get to wan of pfsense.

Can you see the traffic at the lan interface get sent to 114?
Yes, See the new sniff on the LAN Side. I see the same traffic there too

Do you see the states get opened? What if you try a passive connection vs active. Where the client will make the connection to the server, ie so 114 will make a connection to 182 on the port 182 says to connect too.
this trace was PASv and failed as wwell.
yes the states are opened ( at least I think they are correct , See the attached shot.

As to the IPs being changed - remember in my post where I said to set everything else in the task to passthru ;) "You add an anon task, set everything to passthrough except the text part. " ;)
I am little tired these day or is it just dumb! :-)

Why would you be doing an outbound nat, other than automatic? Do you have some strange outbound net setup? I would assume all traffic from lan of pfsense going to wan network would get natted to the pfsense wan IP. Ie the 114 address.

Outbound NAT is automatic. no rules have been changed for many months and has only just stopped working :-(

You can run into problems if that port is already in use, sure. Try a passive connection, set on 114 when you talk to the 182 server. What does the sniff show then?
See attached Sniff from inside using PASV, This connection failed too

Just to clarify - your the client in this conversation right, your 114 is behind pfsense. and 182 is some public ftp server? Or is 182 behind pfsense?
yes that is correct, Teh remote site is not behind an firewall ( as far as I know, I d not have anythig to do with that host)

Screenshot-4.png_thumb
[Capture LAN- FailFTP_anon.pcapng.txt](/public/imported_attachments/1/Capture LAN- FailFTP_anon.pcapng.txt)

johnpoz

ok there is not passive traffic in that sniff. I see the passive command but then you see port command and the server coming from 182

source 20 to port 56488.. But seems your client on 192.168.53.26 doesn't answer.

Do you have some firewall running on this 192.168 box? Clearly pfsense sent it the traffic – that sniff is clearly on the lan side. But there is no answer back.

I see the passive command where the server on 182 said hey connect to me on port 33133, see the command pasv 129x256 + 109 but there is not traffic from your 192.168 to that IP and port.

so what I see from that sniff, your client never sends traffic on the pasv port that server gave. But then again sends port command and the server sends traffic to that port, that pfsense clearly sent on changing the IP to the client 192.168 IP -- but the client never answers.

edit: does this client have more than 1 interface, or routes where it would of sent that passive traffic to something else than pfsense, or try and answer that syn traffic from 20 somewhere else?

again clearly pfsense put on the wire to that 192.168.53.26 the data traffic it got from the server, but there is no answer from the client in that sniff. So yeah data would fail.

activetraffic.png_thumb

kcpoole

@johnpoz:

edit: does this client have more than 1 interface, or routes where it would of sent that passive traffic to something else than pfsense, or try and answer that syn traffic from 20 somewhere else?

again clearly pfsense put on the wire to that 192.168.53.26 the data traffic it got from the server, but there is no answer from the client in that sniff. So yeah data would fail.

Ok thanks
No the Client does not have a firewall on it, and there is only 1 NIC on each client,

Any thoughts on Why the client would not respond? not forgetting I have tried 3 different clients behind the firewall, Win 2003, 2008, and my debian server. None of which work. The debian server is my own FTP host which I also cannot now connect to.

Ken

johnpoz

can we draw up your network, and work through it

From what I can see with the passive command your client didn't try and connect to the IP and port given, and instead sent port command again, that the ftp server tried to connect too and pfsense sent on the lan to the 192.168 address. But that ftp server never responded.

None of this points to a pfsense problem. It seems the helper is changing the private ips to the public ones, and creating the states to allow the active connection from 20 to come in and sends it on to the ftp server.

You sniffed at both the wan and the lan interfaces and don't see where pfsense is doing anything wrong or not doing anything. It changes the IPs and forwards on the traffic it gets in answer to the port command..

Here the thing, from a client talking pasv to a ftp server on the pubic internet pfsense ftp helper doesn't really do anything. Your client makes a connection to the servers port 21, this is no different than a client going to a website. If the client then does a passive connection - the server says hey connect to me on port X, the client is then suppose to go connect to that port. Again pfsense ftp helper is not involved, your just a client making a connection to some port just like a web site.

Only if your server is behind pfsense and client come from the public does the passive does ftp helper have to do anything it has to open the port the server told the client to connect to and forward it to the server. And possible change the IP from a private to public if the servers pasv command gave a private.

if the client is on the public internet and does a active to your server behind pfsense. Pfsense does nothing different than if your ftp server was going to some website.

If the client is behind pfsense talking to a ftp server on public and does active connection, then ftp helper has to change the IP in the port command and to the public one and allow and forward the port that the sever on the public internet is going to talk to from port 20.

Since pfsense is not really doing anything in a client behind pfsense going to a pubic ftp server using passive, lets troubleshoot that problem. From a box on your 192 network, try and connect to say ftp.microsoft.com using passive!! Make sure the client support passive and easy to change and watch the connection. For example filezilla shows you what is happening and can easy be changed from active to passive mode on the client. If you sniff on pfsense wan, and client we can validate that pfsense is passing traffic and that client from the filezilla log and sniff that it got the command for what IP and port to connect to and that it actually tries to connect, and sniff on wan of pfsense will show us that connection went out to the internet.

kejianshi

You get A+ for patience. (-:

johnpoz

It is wearing thin ;) But would be easier if had access to a box inside his network, and pfsense..

While ftp can be a PITA, its not a complicated protocol. I really don't understand why anyone still uses it any more. Use sftp - its 1 port, its encrypted. You don't have these pasv vs active on a different session to deal with, etc..

I really don't see why anyone still uses ftp, other than maybe anonymous serving up files? If your going to serve them up anonymous - why not just do it over http ;)

kcpoole

@johnpoz:

It is wearing thin ;) But would be easier if had access to a box inside his network, and pfsense..

While ftp can be a PITA, its not a complicated protocol. I really don't understand why anyone still uses it any more. Use sftp - its 1 port, its encrypted. You don't have these pasv vs active on a different session to deal with, etc..

I really don't see why anyone still uses ftp, other than maybe anonymous serving up files? If your going to serve them up anonymous - why not just do it over http ;)

FTP in use because that is why the clients website provider uses :-(
I have asked is they support sftp or SCP to no avail..

Re network diagram is super simple so did not think necessary to doc
192.168.53.x –--> 192.168.53.1 (Pfsense) 114.111.141.50 ------> whlac.org.au (ftp server)

for inbound to my own ftp server ( used for testing)
192.168.53.5 (my internal FTP server) ---- 192.168.53.1 (Pfsense Inbound NAT) ) 114.111.141.50 <------ Any external client

Several internal host have the identical issue

I have just tried using Filezilla on the client and the connection / upload worked fine ! . It still fails using the command line though.
note I am uploading as part of a script and thus the command line is what I am needing to use and thus have not ried anything else

Ken

kcpoole

@kejianshi:

You get A+ for patience. (-:

Hey boys Dont worry OK if that is the attitude. I Dunno why it might be wearing thin 'cos this is a really weird one that has got me stumped. As you say FTP is brain dead simple and shold "Just work" but this does not for some reason.

Thanks for your help John and Sorry to take up your time
Ken

johnpoz

So filezilla works in what test you uploading to whlac.org.au in passive mode?

So 182.50.153.244 is the webhost ftp server you need to send stuff too. And your doing this from something on your 192.168 network.. Why can you not just use passive? What ftp client are scripting to? Windows build int ftp? You can script filezilla easy.. Or you could use winscp again scripts easy.

If on linux what ftp client are you using?

So when you used active connection pfsense changed the IP for your port command, and sent on the syn part of the connection from the server as you saw that on your sniff. But your client did not respond..

So you have something wrong on your client.

When you test from filezilla did you test both active and passive - did that work? Or just the passive worked?

As to webhost not supporting sftp, that is easy enough - change webhosts ;) Run your own vps, etc. Its not like you can not host a website at a billion different places. If one doesn't provide the services you want - move to one that does ;)